Hello there, my Carpenter friend.

The listed items below cover all Carpenter leves from levels 10 to 45, each noting how many turn-ins it takes to progress individual levels (up to five above the minimum acquisition level), and how many it requires to progress five or ten levels up-front.
Some points moving forward:

Each listing assumes you have reached the required level with no experience past 0. Keep this is mind moving forward, because you will rarely ever be at 0 XP right when you reach a level.
Repeatable/Charity/triple turn-in leves are noted with asterisks next to their experience numbers. These listings assume you intend to make full use of these leves and turn in the requirements all three times, and hence their listed XP numbers are three times the base (plus bonuses on HQ turn-ins).
To be 100% honest, I recommend avoiding leves until level 20.
If you are looking for mass-leveling I highly recommend repeatables/triples. If for shorter bursts, Ingenuity may be better suited to your budget (though they require travel).

If you're looking for something more compact to have on hand, head over to my Complete Carpenter Leves Guide.
Most efficient leve-wise options per tier:

While this does show which leves will give you the biggest XP for your allowance punch, the fact of the matter is triple turn-in leves require a considerably higher amount of effort to complete over their counterparts. The majority of leves mentioned in this list here are triple turn-ins. If you're low on leves, they're great. If not, there are now plenty of reasonable XP reward-giving leves at all level ranges.

Level 10: Shielding Sales
Level 15: Nothing to Hide
Level 20: Behind the Mask
Level 25: Armoires of the Rich and Famous
Level 30: Ceremonial Spears
Level 35: Flintstone Flight
Level 40: Spin It Like You Mean It
Level 45: Trident and Error; Incant Now, Think Later

Remember: Crafting XP is not taken into consideration in these numbers!
(If you see any mis-types on the numbers, please let me know. I've gone through these a couple of times looking for mistakes, but they always seem to slip through.)
Level 10 leves

Citizens' Canes (Gridania) - 5132 XP (HQ: 10264 XP)
Requires: 1 Ash Radical
Completions to level: Level 10-11 (11,800 XP): 3 (HQ: 2)
Level 11-12 (15,600 XP): 4 (HQ: 2)
Level 12-13 (19,600 XP): 4 (HQ: 2)
Level 13-14 (23,700 XP): 5 (HQ: 3)
Level 14-15 (26,400 XP): 6 (HQ: 3)
All at once (97100 XP needed): 19 (10)
Straight from 10-20 (300200 XP): 59 (HQ: 30)

Raise the Roof (Gridania) - 6066 XP (HQ: 12132 XP)
Requires: 3 Ash Lumber
Completions to level: Level 10 (11,800 XP): 2 (HQ: 1)
Level 11 (15,600 XP): 3 (HQ: 2)
Level 12 (19,600 XP): 4 (HQ: 2)
Level 13 (23,700 XP): 4 (HQ: 2)
Level 14 (26,400 XP): 5 (HQ: 3)
All at once (97100 XP needed): 17 (9)
Straight from 10-20 (300200 XP): 50 (HQ: 25)

On the Move (Gridania) - 4460 XP (HQ: 8920 XP)
Requires: 1 Ragstone Grinding Wheel
Completions to level: Level 10-11 (11,800 XP): 3 (HQ: 2)
Level 11-12 (15,600 XP): 4 (HQ: 2)
Level 12-13 (19,600 XP): 5 (HQ: 3)
Level 13-14 (23,700 XP): 6 (HQ: 3)
Level 14-15 (26,400 XP): 6 (HQ: 3)
All at once (97100 XP needed): 22 (11)
Straight from 10-20 (300200 XP): 68 (HQ: 34)

Shielding Sales (Bentbranch) - 11616 XP (HQ: 23232 XP)
Requires: 1 Feathered Harpoon
Completions to level: Level 10-11 (11,800 XP): 2 (HQ: 1)
Level 11-12 (15,600 XP): 2 (HQ: 1)
Level 12-13 (19,600 XP): 2 (HQ: 1)
Level 13-14 (23,700 XP): 3 (HQ: 2)
Level 14-15 (26,400 XP): 3 (HQ: 2)
All at once (97100 XP needed): 9 (HQ: 5)
Straight from 10-20 (300200 XP): 26 (HQ: 13)

Life's a Stitch (Bentbranch) - 4820 XP (HQ: 9640 XP)
Requires: 1 Ash Spinning Wheel
Completions to level: Level 10-11 (11,800 XP): 3 (HQ: 2)
Level 11-12 (15,600 XP): 4 (HQ: 2)
Level 12-13 (19,600 XP): 5 (HQ: 3)
Level 13-14 (23,700 XP): 5 (HQ: 3)
Level 14-15 (26,400 XP): 6 (HQ: 3)
All at once (97100 XP needed): 21 (HQ: 11)
Straight from 10-20 (300200 XP): 63 (HQ: 32)

Say It with Spears (Bentbranch) - 5132 XP (HQ: 10264 XP)
Requires: 1 Feathered Harpoon
Completions to level: Level 10-11 (11,800 XP): 3 (HQ: 2)
Level 11-12 (15,600 XP): 4 (HQ: 2)
Level 12-13 (19,600 XP): 4 (HQ: 2)
Level 13-14 (23,700 XP): 5 (HQ: 3)
Level 14-15 (26,400 XP): 6 (HQ: 3)
All at once (97100 XP needed): 19 (10)
Straight from 10-20 (300200 XP): 59 (HQ: 30)
Level 15 leves

Re-crating the Scene (Gridania) - 8454 XP (HQ: 16908 XP)
Requires: 1 Iron Spear
Completions to level: Level 15-16 (30,500 XP): 4 (HQ: 2)
Level 16-17 (35,400 XP): 5 (HQ: 3)
Level 17-18 (40,500 XP): 5 (HQ: 3)
Level 18-19 (45,700 XP): 6 (HQ: 3)
Level 19-20 (51,000 XP): 7 (HQ: 4)
All at once (203,100 XP needed): 25 (HQ: 13)
Straight from 15-25 (561,200 XP): 67 (HQ: 34)

Driving up the Wall (Gridania) - 12172 XP (HQ: 124344 XP)
Requires: 3 Elm Lumber
Completions to level: Level 15-16 (30,500 XP): 3 (HQ: 2)
Level 16-17 (35,400 XP): 3 (HQ: 2)
Level 17-18 (40,500 XP): 4 (HQ: 2)
Level 18-19 (45,700 XP): 4 (HQ: 2)
Level 19-20 (51,000 XP): 5 (HQ: 3)
All at once (203,100 XP needed): 17 (HQ: 9)
Straight from 15-25 (561,200 XP): 47 (HQ: 24)

Nightmare on My Street (Gridania) - 8764 XP (HQ: 17528 XP)
Requires: 1 Elm Cane
Completions to level: Level 15-16 (30,500 XP): 4 (HQ: 2)
Level 16-17 (35,400 XP): 5 (HQ: 3)
Level 17-18 (40,500 XP): 5 (HQ: 3)
Level 18-19 (45,700 XP): 6 (HQ: 3)
Level 19-20 (51,000 XP): 6 (HQ: 3)
All at once (203,100 XP needed): 24 (HQ: 12)
Straight from 15-25 (561,200 XP): 65 (HQ: 33)

What You Need (Hawthorne Hut) - 7744 XP (HQ: 15488 XP)
Requires: 1 Square Ash Shield
Completions to level: Level 15-16 (30,500 XP): 4 (HQ: 2)
Level 16-17 (35,400 XP): 5 (HQ: 3)
Level 17-18 (40,500 XP): 6 (HQ: 3)
Level 18-19 (45,700 XP): 6 (HQ: 3)
Level 19-20 (51,000 XP): 7 (HQ: 4)
All at once (203,100 XP needed): 27 (HQ: 14)
Straight from 15-25 (561,200 XP): 73 (HQ: 37)

Bowing to Necessity (Hawthorne Hut) - 11616 XP (HQ: 23232 XP)
Requires: 1 Ash Shortbow
Completions to level: Level 15-16 (30,500 XP): 3 (HQ: 2)
Level 16-17 (35,400 XP): 4 (HQ: 2)
Level 17-18 (40,500 XP): 4 (HQ: 2)
Level 18-19 (45,700 XP): 4 (HQ: 2)
Level 19-20 (51,000 XP): 5 (HQ: 3)
All at once (203,100 XP needed): 18 (HQ: 9)
Straight from 15-25 (561,200 XP): 49 (HQ: 25)

Nothing to Hide (Hawthorne Hut) - 12218 XP (HQ: 24436 XP)
Requires: 1 Ash Mask (Lapis Lazuli)
Completions to level: Level 15-16 (30,500 XP): 3 (HQ: 2)
Level 16-17 (35,400 XP): 3 (HQ: 2)
Level 17-18 (40,500 XP): 4 (HQ: 2)
Level 18-19 (45,700 XP): 4 (HQ: 2)
Level 19-20 (51,000 XP): 5 (HQ: 3)
All at once (203,100 XP needed): 17 (HQ: 9)
Straight from 15-25 (561,200 XP): 46 (HQ: 23)
Level 20 leves

As the Worm Turns (Gridania) - 12746 XP (HQ: 25492 XP)
Requires: 1 Yew Radical
Completions to level: Level 20-21 (56,600 XP): 5 (HQ: 3)
Level 21-22 (63,900 XP): 6 (HQ: 3)
Level 22-23 (71,400 XP): 6 (HQ: 3)
Level 23-24 (79,100 XP): 7 (HQ: 4)
Level 24-25 (87,100 XP): 7 (HQ: 4)
All at once (358,100 XP needed): 29 (HQ: 15)
Straight from 20-30 (984,000 XP): 78 (HQ: 39)

Behind the Mask (Gridania) - 21993* XP (HQ: 43986* XP)
Requires: 3 Ash Mask (Lapis Lazuli) (9 total)
Completions to level: Level 20-21 (56,600 XP): 3 (HQ: 2)
Level 21-22 (63,900 XP): 3 (HQ: 2)
Level 22-23 (71,400 XP): 4 (HQ: 2)
Level 23-24 (79,100 XP): 4 (HQ: 2)
Level 24-25 (87,100 XP): 4 (HQ: 2)
All at once (358,100 XP needed): 17 (HQ: 9)
Straight from 20-30 (984,000 XP): 45 (HQ: 23)

Militia on My Mind (Gridania) - 18328 XP (HQ: 36656 XP)
Requires: 1 Iron Lance
Completions to level: Level 20-21 (56,600 XP): 4 (HQ: 2)
Level 21-22 (63,900 XP): 4 (HQ: 2)
Level 22-23 (71,400 XP): 4 (HQ: 2)
Level 23-24 (79,100 XP): 5 (HQ: 3)
Level 24-25 (87,100 XP): 5 (HQ: 3)
All at once (358,100 XP needed): 20 (HQ: 10)
Straight from 20-30 (984,000 XP): 54 (HQ: 27)

Wall Not Found (Quarrymill) - 18524 XP (HQ: 37048 XP)
Requires: 1 Walnut Lumber
Completions to level: Level 20-21 (56,600 XP): 4 (HQ: 2)
Level 21-22 (63,900 XP): 4 (HQ: 2)
Level 22-23 (71,400 XP): 4 (HQ: 2)
Level 23-24 (79,100 XP): 5 (HQ: 3)
Level 24-25 (87,100 XP): 5 (HQ: 3)
All at once (358,100 XP needed): 20 (HQ: 10)
Straight from 20-30 (984,000 XP): 54 (HQ: 27)

Polearms Aplenty (Quarrymill) - 15219* XP (HQ: 30438* XP)
Requires: 3 Iron Spears (9 total)
Completions to level: Level 20-21 (56,600 XP): 4 (HQ: 2)
Level 21-22 (63,900 XP): 5 (HQ: 3)
Level 22-23 (71,400 XP): 5 (HQ: 3)
Level 23-24 (79,100 XP): 6 (HQ: 3)
Level 24-25 (87,100 XP): 6 (HQ: 3)
All at once (358,100 XP needed): 24 (HQ: 12)
Straight from 20-30 (984,000 XP): 65 (HQ: 33)

Grinding It Out (Quarrymill) - 13250 XP (HQ: 26500 XP)
Requires: 1 Mudstone Grinding Wheel
Completions to level: Level 20-21 (56,600 XP): 5 (HQ: 3)
Level 21-22 (63,900 XP): 5 (HQ: 3)
Level 22-23 (71,400 XP): 6 (HQ: 3)
Level 23-24 (79,100 XP): 6 (HQ: 3)
Level 24-25 (87,100 XP): 7 (HQ: 4)
All at once (358,100 XP needed): 28 (HQ: 14)
Straight from 20-30 (984,000 XP): 75 (HQ: 38)
Level 25 leves

Armoires of the Rich and Famous (Gridania) - 33345* XP (HQ: 66690* XP)
Requires: 5 Walnut Lumber (15 total)
Completions to level: Level 25-26 (95,200 XP): 3 (HQ: 2)
Level 26-27 (109,800 XP): 4 (HQ: 2)
Level 27-28 (124,800 XP): 4 (HQ: 2)
Level 28-29 (140,200 XP): 5 (HQ: 3)
Level 29-30 (155,900 XP): 5 (HQ: 3)
All at once (625,900 XP needed): 19 (HQ: 10)
Straight from 25-35 (1,575,300 XP): 48 (HQ: 24)

Daddy's Little Girl (Gridania) - 19770 XP (HQ: 39540 XP)
Requires: 1 Viper-crested Round Shield
Completions to level: Level 25-26 (95,200 XP): 5 (HQ: 3)
Level 26-27 (109,800 XP): 6 (HQ: 3)
Level 27-28 (124,800 XP): 7 (HQ: 4)
Level 28-29 (140,200 XP): 8 (HQ: 4)
Level 29-30 (155,900 XP): 8 (HQ: 4)
All at once (625,900 XP needed): 32 (HQ: 16)
Straight from 25-35 (1,575,300 XP): 80 (HQ: 40)

Tools for the Tools (Gridania) - 31420 XP (HQ: 62840 XP)
Requires: 1 Silver Battle Fork
Completions to level: Level 25-26 (95,200 XP): 4 (HQ: 2)
Level 26-27 (109,800 XP): 4 (HQ: 2)
Level 27-28 (124,800 XP): 4 (HQ: 2)
Level 28-29 (140,200 XP): 5 (HQ: 3)
Level 29-30 (155,900 XP): 5 (HQ: 3)
All at once (625,900 XP needed): 20 (HQ: 10)
Straight from 25-35 (1,575,300 XP): 51 (HQ: 26)

Toys of Summer (Quarrymill) - 29450 XP (HQ: 58900 XP)
Requires: 1 Steel Spear
Completions to level: Level 25-26 (95,200 XP): 4 (HQ: 2)
Level 26-27 (109,800 XP): 4 (HQ: 2)
Level 27-28 (124,800 XP): 5 (HQ: 3)
Level 28-29 (140,200 XP): 5 (HQ: 3)
Level 29-30 (155,900 XP): 6 (HQ: 3)
All at once (625,900 XP needed): 22 (HQ: 11)
Straight from 25-35 (1,575,300 XP): 81 (HQ: 41)

Storm of Swords (Quarrymill) - 22066 XP (HQ: 44132 XP)
Requires: 1 Elm Macuahuitl
Completions to level: Level 25-26 (95,200 XP): 5 (HQ: 3)
Level 26-27 (109,800 XP): 5 (HQ: 3)
Level 27-28 (124,800 XP): 6 (HQ: 3)
Level 28-29 (140,200 XP): 7 (HQ: 4)
Level 29-30 (155,900 XP): 8 (HQ: 4)
All at once (625,900 XP needed): 29 (HQ: 15)
Straight from 25-35 (1,575,300 XP): 72 (HQ: 36)

Heal Away (Quarrymill) - 25515* XP (HQ: 51030* XP)
Requires: 3 Yew Crooks (9 total)
Completions to level: Level 25-26 (95,200 XP): 4 (HQ: 2)
Level 26-27 (109,800 XP): 5 (HQ: 3)
Level 27-28 (124,800 XP): 5 (HQ: 3)
Level 28-29 (140,200 XP): 6 (HQ: 3)
Level 29-30 (155,900 XP): 7 (HQ: 4)
All at once (625,900 XP needed): 25 (HQ: 13)
Straight from 25-35 (1,575,300 XP): 62 (HQ: 31)
Level 30 leves

An Expected Tourney (Gridania) - 30282 XP (HQ: 60564 XP)
Requires: 1 Ash Cavalry Bow
Completions to level: Level 30-31 (162,500 XP): 6 (HQ: 3)
Level 31-32 (175,900 XP): 6 (HQ: 3)
Level 32-33 (189,600 XP): 7 (HQ: 4)
Level 33-34 (203,500 XP): 7 (HQ: 4)
Level 34-35 (217,900 XP): 8 (HQ: 4)
All at once (949,400 XP needed): 32 (HQ: 16)
Straight from 30-40 (2,290,520 XP): 76 (HQ: 38)

Knock on Wood (Gridania) - 49000 XP (HQ: 98000 XP)
Requires: 1 Walnut Macuahuitl
Completions to level: Level 30-31 (162,500 XP): 4 (HQ: 2)
Level 31-32 (175,900 XP): 4 (HQ: 2)
Level 32-33 (189,600 XP): 4 (HQ: 2)
Level 33-34 (203,500 XP): 5 (HQ: 3)
Level 34-35 (217,900 XP): 5 (HQ: 3)
All at once (949,400 XP needed): 20 (HQ: 10)
Straight from 30-40 (2,290,520 XP): 47 (HQ: 24)

Ceremonial Spears (Gridania) - 53010* XP (HQ: 106020* XP)
Requires: 3 Steel Spears (9 total)
Completions to level: Level 30-31 (162,500 XP): 4 (HQ: 2)
Level 31-32 (175,900 XP): 4 (HQ: 2)
Level 32-33 (189,600 XP): 4 (HQ: 2)
Level 33-34 (203,500 XP): 4 (HQ: 2)
Level 34-35 (217,900 XP): 5 (HQ: 3)
All at once (949,400 XP needed): 18 (HQ: 9)
Straight from 30-40 (2,290,520 XP): 44 (HQ: 22)

The Long Lance of the Law (Costa del Sol) - 41661* XP (HQ: 83322* XP)
Requires: 3 Steel Halberd (9 total)
Completions to level: Level 30-31 (162,500 XP): 4 (HQ: 2)
Level 31-32 (175,900 XP): 5 (HQ: 3)
Level 32-33 (189,600 XP): 5 (HQ: 3)
Level 33-34 (203,500 XP): 5 (HQ: 3)
Level 34-35 (217,900 XP): 6 (HQ: 3)
All at once (949,400 XP needed): 23 (HQ: 12)
Straight from 30-40 (2,290,520 XP): 55 (HQ: 28)

The Lone Bowman (Costa del Sol) - 39900 XP (HQ: 79800 XP)
Requires: 1 Oak Longbow
Completions to level: Level 30-31 (162,500 XP): 5 (HQ: 3)
Level 31-32 (175,900 XP): 5 (HQ: 3)
Level 32-33 (189,600 XP): 5 (HQ: 3)
Level 33-34 (203,500 XP): 6 (HQ: 3)
Level 34-35 (217,900 XP): 6 (HQ: 3)
All at once (949,400 XP needed): 24 (HQ: 12)
Straight from 30-40 (2,290,520 XP): 58 (HQ: 29)

Live Freelance or Die (Costa del Sol) - 39900 XP (HQ: 79800 XP)
Requires: 1 Heavy Steel Lance
Completions to level: Level 30-31 (162,500 XP): 5 (HQ: 3)
Level 31-32 (175,900 XP): 5 (HQ: 3)
Level 32-33 (189,600 XP): 5 (HQ: 3)
Level 33-34 (203,500 XP): 6 (HQ: 3)
Level 34-35 (217,900 XP): 6 (HQ: 3)
All at once (949,400 XP needed): 24 (HQ: 12)
Straight from 30-40 (2,290,520 XP): 58 (HQ: 29)
Level 35 leves

Flintstone Flight (Gridania) - 58800* XP (HQ: 117600* XP)
Requires: 3 Walnut Macuahuitl (9 total)
Completions to level: Level 35-36 (232,320 XP): 4 (HQ: 2)
Level 36-37 (249,900 XP): 5 (HQ: 3)
Level 37-38 (267,800 XP): 5 (HQ: 3)
Level 38-39 (286,200 XP): 5 (HQ: 3)
Level 39-40 (304,900 XP): 6 (HQ: 3)
All at once (1,341,120 XP needed): 23 (HQ: 12)
Straight from 35-45 (3,126,620): 54 (HQ: 27)

A Tree Grew in Gridania (Gridania) - 42114 XP (HQ: 84228 XP)
Requires: 1 Pastoral Oak Cane
Completions to level: Level 35-36 (232,320 XP): 6 (HQ: 3)
Level 36-37 (249,900 XP): 6 (HQ: 3)
Level 37-38 (267,800 XP): 7 (HQ: 4)
Level 38-39 (286,200 XP): 7 (HQ: 4)
Level 39-40 (304,900 XP): 8 (HQ: 4)
All at once (1,341,120 XP needed): 32 (HQ: 16)
Straight from 35-45 (3,126,620): 75 (HQ: 38)

Stay on Target (Gridania) - 61552 XP (HQ: 123104 XP)
Requires: 1 Yarzonshell Harpoon
Completions to level: Level 35-36 (232,320 XP): 4 (HQ: 3)
Level 36-37 (249,900 XP): 5 (HQ: 3)
Level 37-38 (267,800 XP): 5 (HQ: 3)
Level 38-39 (286,200 XP): 5 (HQ: 3)
Level 39-40 (304,900 XP): 5 (HQ: 3)
All at once (1,341,120 XP needed): 22 (HQ: 11)
Straight from 35-45 (3,126,620): 51 (HQ: 26)

Bend It Like Durendaire (Observatorium) - 54510* XP (HQ: 109020* XP)
Requires: 3 Ash Cavalry Bow (9 total)
Completions to level: Level 35-36 (232,320 XP): 5 (HQ: 3)
Level 36-37 (249,900 XP): 5 (HQ: 3)
Level 37-38 (267,800 XP): 5 (HQ: 3)
Level 38-39 (286,200 XP): 5 (HQ: 3)
Level 39-40 (304,900 XP): 6 (HQ: 3)
All at once (1,341,120 XP needed): 25 (HQ: 13)
Straight from 35-45 (3,126,620): 58 (HQ: 29)

Grippy When Wet (Observatorium) - 41034 XP (HQ: 82068 XP)
Requires: 1 1 Mythril Cavalry Bow
Completions to level: Level 35-36 (232,320 XP): 6 (HQ: 3)
Level 36-37 (249,900 XP): 7 (HQ: 4)
Level 37-38 (267,800 XP): 7 (HQ: 4)
Level 38-39 (286,200 XP): 7 (HQ: 4)
Level 39-40 (304,900 XP): 8 (HQ: 4)
All at once (1,341,120 XP needed): 33 (HQ: 17)
Straight from 35-45 (3,126,620): 77 (HQ: 39)

The Cold, Cold Ground (Observatorium) - 44238 XP (HQ: 88476 XP)
Requires: 1 Oak Pattens
Completions to level: Level 35-36 (232,320 XP): 6 (HQ: 3)
Level 36-37 (249,900 XP): 6 (HQ: 3)
Level 37-38 (267,800 XP): 7 (HQ: 4)
Level 38-39 (286,200 XP): 7 (HQ: 4)
Level 39-40 (304,900 XP): 7 (HQ: 4)
All at once (1,341,120 XP needed): 31 (HQ: 16)
Straight from 35-45 (3,126,620): 71 (HQ: 36)
Level 40 leves

Greenstones for Greenhorns (Gridania) - 56534 XP (HQ: 113068 XP)
Requires: 1 Jade Crook
Completions to level: Level 40-41 (324,000 XP): 6 (HQ: 3)
Level 41-42 (340,200 XP): 7 (HQ: 4)
Level 42-43 (356,800 XP): 7 (HQ: 4)
Level 43-44 (373,700 XP): 7 (HQ: 4)
Level 44-45 (390,800 XP): 7 (HQ: 4)
All at once (1,785,500 XP needed): 32 (HQ: 16)
Straight from 40-50 (4,125,800): 73 (HQ: 37)

Spin It Like You Mean It (Gridania) - 96147* XP (HQ: 192294* XP)
Requires: 3 Mahogany Spinning Wheel (9 total)
Completions to level: Level 40-41 (324,000 XP): 4 (HQ: 2)
Level 41-42 (340,200 XP): 4 (HQ: 2)
Level 42-43 (356,800 XP): 4 (HQ: 2)
Level 43-44 (373,700 XP): 4 (HQ: 2)
Level 44-45 (390,800 XP): 5 (HQ: 3)
All at once (1,785,500 XP needed): 19 (HQ: 10)
Straight from 40-50 (4,125,800): 43 (HQ: 22)

The Arsenal of Theocracy (Gridania) - 84802 XP (HQ: 169604 XP)
Requires: 1 Cobalt Halberd
Completions to level: Level 40-41 (324,000 XP): 4 (HQ: 2)
Level 41-42 (340,200 XP): 5 (HQ: 3)
Level 42-43 (356,800 XP): 5 (HQ: 3)
Level 43-44 (373,700 XP): 5 (HQ: 3)
Level 44-45 (390,800 XP): 5 (HQ: 3)
All at once (1,785,500 XP needed): 22 (HQ: 11)
Straight from 40-50 (4,125,800): 49 (HQ: 25)

The Turning Point (Whitebrim) - 55774 XP (HQ: 111548 XP)
Requires: 1 Garnet Grinding Wheel
Completions to level: Level 40-41 (324,000 XP): 6 (HQ: 3)
Level 41-42 (340,200 XP): 7 (HQ: 4)
Level 42-43 (356,800 XP): 7 (HQ: 4)
Level 43-44 (373,700 XP): 7 (HQ: 4)
Level 44-45 (390,800 XP): 8 (HQ: 4)
All at once (1,785,500 XP needed): 33 (HQ: 17)
Straight from 40-50 (4,125,800): 74 (HQ: 37)

A Winning Combo (Whitebrim) - 53414 XP (HQ: 106828 XP)
Requires: 1 Oak Composite Bow
Completions to level: Level 40-41 (324,000 XP): 7 (HQ: 4)
Level 41-42 (340,200 XP): 7 (HQ: 4)
Level 42-43 (356,800 XP): 7 (HQ: 4)
Level 43-44 (373,700 XP): 7 (HQ: 4)
Level 44-45 (390,800 XP): 8 (HQ: 4)
All at once (1,785,500 XP needed): 33 (HQ: 17)
Straight from 40-50 (4,125,800): 74 (HQ: 37)

Ready for a Rematch (Whitebrim) - 77751* XP (HQ: 155502* XP)
Requires: 3 Mythril Lance (9 total)
Completions to level: Level 40-41 (324,000 XP): 5 (HQ: 3)
Level 41-42 (340,200 XP): 5 (HQ: 3)
Level 42-43 (356,800 XP): 5 (HQ: 3)
Level 43-44 (373,700 XP): 5 (HQ: 3)
Level 44-45 (390,800 XP): 6 (HQ: 3)
All at once (1,785,500 XP needed): 23 (HQ: 12)
Straight from 40-50 (4,125,800): 154 (HQ: 77)
Level 45 leves

You Do the Heavy Lifting (Gridania) - 79629* XP (HQ: 159258* XP)
Requires: 5 Mahogany Lumber (15 total)
Completions to level: Level 45-46 (408,200 XP): 6 (HQ: 3)
Level 46-47 (437,600 XP): 6 (HQ: 3)
Level 47-48 (467,500 XP): 6 (HQ: 3)
Level 48-49 (498,000 XP): 7 (HQ: 4)
Level 49-50 (529,000 XP): 7 (HQ: 4)
All at once (2,340,300 XP needed): 30 (HQ: 15)

Clogs of War (Gridania) - 71040 XP (HQ: 142080 XP)
Requires: 1 Mahogany Pattens
Completions to level: Level 45-46 (408,200 XP): 6 (HQ: 3)
Level 46-47 (437,600 XP): 7 (HQ: 4)
Level 47-48 (467,500 XP): 7 (HQ: 4)
Level 48-49 (498,000 XP): 8 (HQ: 4)
Level 49-50 (529,000 XP): 8 (HQ: 4)
All at once (2,340,300 XP needed): 33 (HQ: 17)

Trident and Error (Gridania) - 103656 XP (HQ: 207312 XP)
Requires: 1 Cobalt Trident
Completions to level: Level 45-46 (408,200 XP): 4 (HQ: 2)
Level 46-47 (437,600 XP): 5 (HQ: 3)
Level 47-48 (467,500 XP): 5 (HQ: 3)
Level 48-49 (498,000 XP): 5 (HQ: 3)
Level 49-50 (529,000 XP): 6 (HQ: 3)
All at once (2,340,300 XP needed): 23 (HQ: 12)

Bowing to Greater Power (St. Coinach's Find) - 67146 XP (HQ: 134292 XP)
Requires: 1 Yew Longbow
Completions to level: Level 45-46 (408,200 XP): 7 (HQ: 4)
Level 46-47 (437,600 XP): 7 (HQ: 4)
Level 47-48 (467,500 XP): 7 (HQ: 4)
Level 48-49 (498,000 XP): 8 (HQ: 4)
Level 49-50 (529,000 XP): 8 (HQ: 4)
All at once (2,340,300 XP needed): 35 (HQ: 18)

Bow Down to Magic (St. Coinach's Find) - 72932 XP (HQ: 145864 XP)
Requires: 1 Crab Bow
Completions to level: Level 45-46 (408,200 XP): 6 (HQ: 3)
Level 46-47 (437,600 XP): 7 (HQ: 4)
Level 47-48 (467,500 XP): 7 (HQ: 4)
Level 48-49 (498,000 XP): 7 (HQ: 4)
Level 49-50 (529,000 XP): 8 (HQ: 4)
All at once (2,340,300 XP needed): 33 (HQ: 17)

Incant Now, Think Later (St. Coinach's Find) - 101763* XP (HQ: 203526* XP)
Requires: 3 Jade Crook (9 total)
Completions to level: Level 45-46 (408,200 XP): 5 (HQ: 3)
Level 46-47 (437,600 XP): 5 (HQ: 3)
Level 47-48 (467,500 XP): 5 (HQ: 3)
Level 48-49 (498,000 XP): 5 (HQ: 3)
Level 49-50 (529,000 XP): 6 (HQ: 3)
All at once (2,340,300 XP needed): 23 (HQ: 12)

The listed experience amounts are the bare minimum. Multiple high quality turn-ins will result in much more XP.

(I will be error-combing this article this evening! 9/25)
Level 20

Gridania - Behind the Mask
Requires: 3 Ash Mask (Lapis Lazuli) (7331 XP)
Ash Mask (Lapis Lazuli) components:
1 Ice Shard
1 Wind Shard
1 Clove Oil
1 Lapis Lazuli
1 Leather
1 Ash Lumber

Quarrymill - Polearms Aplenty (5073 XP)
Requires: 3 Iron Spear
Iron Spear components:
1 Ice Shard
1 Wind Shard
1 Clove Oil
1 Iron Ingot
1 Elm Lumber
Level 25

Gridania - Armoires of the Rich and Famous (11115 XP)
Requires: 5 Walnut Lumber
Walnut Lumber components:
2 Wind Shard
3 Walnut Log

Quarrymill - Heal Away (8505 XP)
Requires: 3 Yew Crook
Yew Crook components:
2 Ice Shard
2 Wind Shard
1 Yew Lumber
1 Beastkin Blood
Level 30

Gridania - Ceremonial Spears (17670 XP)
Requires: 3 Steel Spear
Steel Speer components:
3 Ice Shard
3 Wind Shard
1 Steel Ingot
1 Walnut Lumber
1 Crab Oil

Costa del Sol - The Long Lance of the Law (13887 XP)
Requires: 3 Steel Halberd
Steel Halberd components:
3 Wind Shard
2 Ice Shard
1 Walnut Lumber
1 Steel Ingot
1 Iron Ingot
1 Aldgoat Leather
Level 35

Gridania - Flintstone Flight (19600 XP)
Requires: 3 Walnut Macuahuitl
Walnut Macauhuitl components:
3 Ice Shard
4 Wind Shard
2 Wyvern Obsidian
1 Walnut Lumber

Coerthas (Observatorium) - Bend It Like Durendaire (18170 XP)
Requires: 3 Ash Cavalry Bow
Ash Cavalry Bow components:
3 Ice Shard
3 Wind Shard
1 Steel Ingot
1 Beast Sinew
2 Ash Lumber
1 Oak Branch
Level 40

Gridania - Spin It Like You Mean It (32049 XP)
Requires: 3 Mahogany Spinning Wheel
Mahogany Spinning Wheel components:
4 Ice Shard
5 Wind Shard
2 Mythril Rivets
2 Mahogany Lumber

Coerthas - Ready for a Rematch (25917 XP)
Requires: 3 Mythril Lance
Mythril Lance components:
4 Ice Shard
4 Wind Shard
1 Mythril Ingot
1 Boar Leather
1 Oak Lumber
Level 45

Gridania - You Do the Heavy Lifting (26543 XP)
Requires: 5 Mahogany Lumber
Mahogany Lumber components:
5 Wind Shard
3 Mahogany Log

Mor Dhona - Incant Now, Think Later (33921 XP)
Requires: 3 Jade Crook
Jade Crook components:
5 Ice Shard
5 Wind Shard
1 Jadeite
1 Mahogany Lumber
1 Spoken Blood
1 Horn Glue