I found this at a site and decided to post, enjoy, its pretty helpfull
:)
Materials Needed:

369 x Light Leather
586 x Medium Leather
389 x Heavy Leather
661 x Thick Leather
340 x Rugged Leather
8 x Cured Heavy Hide
5 x Iron Buckles
112 x Turtle Scales
4 x Wildvine
2 x Cured Thick Hides
In addition for the leatherworking quests you need an extra 10 Thick Leather and 7 Wildvine.

1 - 45
49 x Light Leather Armour Kits - 49 x Light Leather

45 - 55
16 x Handstiched Leather Cloaks - 32 x Light Leather

55 - 100
47 x Embossed Leather Gloves - 141 x Light Leather

100 - 123
29 x Fine Leather Belts - 174 x Light Leather
- 369 x Light Leather total

123 - 137
16 x Dark Leather Boots - 64 x Medium Leather

137 - 155
24 x Dark Leather Pants - 288 x Medium Leather

155 - 165
10 x Hillsman Leather Gloves - 140 x Medium Leather

165 - 180
19 x Heavy Armour Kits - 95 x Heavy Leather

180 - 183
7 x Hillsman Leather Gloves (green) - 98 x Medium Leather
- 586 x Medium Leather total

183 - 191
8 x Barbaric Shoulders - 64 x Heavy Leather & 8 x Cured Heavy Hide

191 - 196
5 x Barbaric Harnesses - 70 x Heavy Leather & 5 x Iron Buckles

196-206
10 x Dusky Bracers - 160 x Heavy Leather
- 389 x Heavy Leather, 8 x Cured Heavy Hide & 5 x Iron Buckles total

206-220
14 x Thick Leather Armour Kits (6 for Leatherworking quest) - 70 x Thick Leather

220-225
5 x Nightscape Headbands (2 for Leatherworking quest) - 25 x Thick Leather

225-227
2 x Turtle Scale Breastplates (Leatherworking quest) - 12 x Thick Leather & 24 x Turtle Scales

227-229
2 x Turtle Scale Gloves (Leatherworking quest) – 12 x Thick Leather & 16 x Turtle Scales

229-230
2 x Nightscape Tunics (Leatherworking quest) - 14 x Thick Leather

230-232
4 x Nightscape Headbands - 20 x Thick Leather

232-233
2 x Turtle Scale Bracers (Leatherworking quest) - 16 x Thick Leather & 24 x Turtle Scales

233-235
2 x Turtle Scale Helms (Leatherworking quest) - 28 x Thick Leather & 48 x Turtle Scales

235-237
2 x Nightscape Pants (Leatherworking quest) - 28 x Thick Leather

237-239
2 x Nightscape Boots (Leatherworking quest) - 32 x Thick Leather

239-240
1 x Wild Leather Vest (Tribal Leatherworking quest) - 12 x Thick Leather, 2 x Wildvine & 1 x Cured Thick Hide

240-241
1 x Wild Leather Helmet (Tribal Leatherworking quest) - 10 x Thick Leather, 2 x Wildvine & 1 x Cured Thick Hide

241-250
9 x Nightscape Pants - 126 x Thick Leather

250-265
16 x Nightscape Boots - 256 x Thick Leather
- 661 x Thick Leather total

265-285
20 x Wicked Leather Bracers - 160 x Rugged Leather

285-300
15 x Wicked Leather Headbands - 180 x Rugged Leather
- 340 x Rugged Leather total

Notes:
In general I have tried to keep as much as possible to the main normal leather types, light, medium, heavy, thick and rugged. This is because it always easier to buy them on the auction house, whereas other ingredients are more difficult to obtain, and therefore more expensive. I haven't mentioned the ingredients that can be bought from vendors, since they are easy to obtain. I ran into trouble around the 180 mark, where most recipes require extra ingredient and I bought whatever had the cheapest buyout on the AH to get me there. Have a look to see what's cheapest at the time for you.

I could have used a lot less thick leather and started on rugged armour kits at 250, but at that time the price of rugged leather was high enough for it to be worth using huge amounts of thick instead (probably because I did this the week before the Darkmoon Faire was in town). If you can get the rugged leather cheaper it's probably worth switching earlier (5 rugged leather Vs 15 thick leather).

I have mostly kept to trainer taught recipes. The exceptions to this are the recipes gained through the leatherworking quests and the recipes for Wicked Leather Bracer and Headband, which I bought on the auction house for 5 and 2 gold respectively (you could substitute Wicked Leather Gauntlet for Wicked Leather Bracers. The recipe is vendor bought from leatherworking suppliers http://www.thotbott.com/?i=11493 it's limited supply though, and after 20 minutes of camping for it I gave up).

I hope that this helps. I know that there are a few places where it could have been done a bit better but I don't think I made too many glaring errors.



Leatherworking 300 to 375 by Highlander on EU-Terenas


300-310
Knothide Leather (5 x Knothide Leather Scraps) x 20 = 100 x Knothide Leather Scraps
N.B. make as many as it takes to get to 310. Your going to need around 725 Knothide leather, so you may aswell get the skill up points for this.

310-320
Wild Draenish Gloves (9 x Knothide Leather, 3 x Rune Thread) x 10

320-325
Thick Draenic Boots (10 x Knothide Leather, 3 x Rune Thread) x 5

325-335
Heavy Knothide Leather (5 x Knothide Leather) x 90

335-340
Thick Draenic Vest (14 x Knothide Leather, 3 x Rune Thread) x 5

340-350
Felscale Breastplate (14 x Knothide Leather, 3 x Fel Scales, 3 x Rune Thread) x 15

N.B. as is common with all the professions now, getting from 350 to 375 is a huge pain. Trainers dont teach anything worthwhile, so the only way to do it, is via random world drop patterns or rep rewards. I'll use rep reward patterns in this guide.

350-355
For those with Scryers rep - Honoured:
Enchanted Felscale Gloves or Boots (4 x Heavy Knothide Leather, 10 x Fel Scales, 6 x Primal Mana) x 5

For those with The Consortium rep - Honored
Fel Leather Boots (10 x Heavy Knothide Leather, 8 x Fel Hide, 8 x Primal Shadow, 3 x Rune Thread) x 5

355-365
You need to be Friendly with Cenarion Expedition for the next part:
Heavy Clefthoof Boots (4 x Heavy Knothide Leather, 20 x Thick Clefthoof Leather, 4 x Primal Earth, 2 x Rune Thread) x 10

N.B. these last 10 points are going to cost you a LOT! (as if the last 15 didn't cost enough!) The materials required are fairly insane and so is the rep requirement, but at the moment I don't see a better way of levelling up.

365-370
If your Exalted with Thrallmar or Honor Hold, then make:
Nethercobra Leg Armor (4 x Heavy Knothide Leather, 4 x Cobra Scales, 8 x Primal Air, 1 x Primal Nether) x 5
N.B. The Cobra Scales and Primal Nether are a major pain to get and I would seriously urge you to work on Sha'tar rep and do the following:

Alternatively, if your exalted with The Sha'tar:
Drums of Battle (2 Heavy Knothide Leather, 1 x Primal Fire, 1 Primal Earth) x 5

N.B. any of the above three will take you to 375, but the material requirement makes for a LOT of farming, as those last 5 points can mean making another 20-30 items.

370-375
Your either going to have to make random world drop epics here with lots of insane material requirements OR go and get exalted with Keepers of Time.
Seeing as the epics are random world drop patterns, I'll go with Keepers of Time rep rewards. You'll need to be level 66 to start your Keepers of Time rep and spend a LOT of time in The Caverns of Time.

Drums of Panic (2 x Heavy Knothide Leather, 2 x Primal Shadow) x 5


Approximate Materials Required

With Scryers Rep
100 x Knothide Leather Scraps
715 x Knothide Leather
100 x Rune Thread
85 x Fel Scales
30 x Primal Mana
200 x Thick Clefthoof Leather
20 x Cobra Scales (if your Thrallmar or Honor Hold exalted)
40 x Primal Air (if your Thrallmar or Honor Hold exalted) or 5 x Primal Earth and 5 x Primal Fire if you went with Sha'tar rep)
5 x Primal Nether (Dont need these if you go with CE or Sha'tar rep)
20 x Primal Earth
10 x Primal Shadow

N.B. if you went with Sha'tar rep at 365, then you'll need 10 less Heavy Knothide Leather, 40 less Primal Air, 5 Primal Earth and 5 less Primal Nether. Gets complicated, dont it?

With The Consortium Rep
100 x Knothide Leather Scraps
675 x Knothide Leather
200 x Thick Clefthoof Leather
40 x Fel Hide
70 x Rune Thread
85 x Fel Scales
20 x Cobra Scales (if your Thrallmar or Honor Hold exalted)
40 x Primal Air (if your Thrallmar or Honor Hold exalted) or 5 x Primal Earth and 5 x Primal Fire if you went with Sha'tar rep)
5 x Primal Nether (Dont need these if you go with CE or Sha'tar rep)
20 x Primal Earth
50 x Primal Shadow
N.B. if you went with Sha'tar rep at 365, then you'll need 10 less Heavy Knothide Leather, 40 less Primal Air, 5 Primal Earth and 5 less Primal Nether.

This unreadable guide you have posted is very outdated.One thing I will point out is you dont need Exalted with Keepers of Time to get the drums of Panic pattern which will carry you to 375 easily.You only need to be Honored ,also many other routes of making things which are cheaper.Also the biggest thing which I find wrong is you say it is best to buy the mats off the AH.(You stated this by the Rugged and Thick leather section).That is the dumbest thing I have ever heard.You will set yourself back from having your Regular and Epic Flyer for about a month or more.There are dailies you can only do with a flying mount.Also the pattern Bag of Many Hides which for those that cannot get Honored with the Keepers of Time easily for what ever reason.You can only get the pattern with a flying mount off the Ogres above the Aldor Rise in Shatt.That pattern is what took me from 370-375 and the mats really arent that hard to farm it requires a bit of traveling which is no biggie.Damn man how long that take you to type lol!

This thread is full of win. Do continue.

Thank you lissan that was very helpful.Grow the hell up loser.

Hi  jacknthabox,

Please don't consider this argumentative but I'm interrested in what method you would suggest instead of the one posted above. In some ways, the above post has much appeal.  As you correctly point out, buying mats in AH is going to cost a LOT of money to go from 340(where I am) to 375.  However, there is the considerration that money isn't the best reason to make the final push.  You mentioned this in other posts.  In the range of 300-335 a leatherworker can make tons of money.  I've done OK. 
Of course, the alternative is farming.  Personally, I hate farming elementals.  Farming Clefthoofs gets boring but it is perhaps less frustrating.  (Its also easier for my elemental shaman).  The above system relies on materials that are common enough in the auction house that a person can get what he needs.  Clefthoof leather is expensive but at least it is fairly easy to buy in great quantities without ruining the economy. 

So I'm interrested in what suggestions you might have instead of this method for levelling beyond 340.  I don't mind setting back my purchase of an epic mount.  I don't have trouble making money without farming. I would waste more time grinding for mats that have awful drop rates.

thanks for any advice.