here are some guide that may help u to level up your crafting skills and avoid all of u loss. if any difficulties happen please leave a comment. tq
Level 300-305
You will need to cut about 15 of the following gems to reach level 305. Their designs can be purchased from your faction's Master Jewelcrafting Trainer in Hellfire Penninsula. Since Wrath of the Lich King came out it's a lot harder to find the gems you need to level from 300-350. That's why I recommend using this guide to make tons of gold so you can offer top dollar for these mats.
Level 305-310
Again, you will need to cut about about 15 of the following gems to level to 310. These designs can also be purchased from your faction's Master Jewelcrafting Trainer in Hellfire Penninsula.
Level 310-320
Design: Fel Iron Blood Ring -> Fel Iron Blood Ring learned from your Master Jewelcrafting Trainer in Hellfire Penninsula. Craft 10 of these. Give/sell these to an enchanter friend or have an enchanter disenchant them for Arcane Dust.
Alternatively at 315 you can start crafting more green gems like you did above. A combination of these two crafts will best suit you depending on what is available from the Auction House or your inventory. But it won't be cheap on the Auction House so make sure you know how to make tons of gold before you waste your 'hard earned' gold. Here is a list of gems that are effective to level from 315-320:
Level 320-325
Design: Azure Moonstone Ring -> Azure Moonstone Ring learned from your Master Jewelcrafting Trainer. These are another great source of Arcane Dust.
Level 325-335
Design: Mercurial Adamantite -> Mercurial Adamantite learned from your Master Jewelcrafting Trainer. Create at least 15 of these, you'll need 15-20 of them while leveling from 335-350.
Level 335-350
Design: Heavy Adamantite Ring -> Heavy Adamantite Ring learned, again, from a Master JC trainer. Use your from above, or make a bunch first.
Level 350-360 (pre Wrath)
There are 34 blue world drop BoE jewelcrafting designs ranging from Bold Living Ruby to Jagged Talasite. Search on the Auction House and run 5 man instances until you get the ones you need/want. Use these designs to level to 360. Each resulting gem will sell for a bit more than it costs to buy the gem needed to make the cut. These are in decent demand on most servers and will be a good part of your jewelcrafting income.
Level 360-375 (pre Wrath)
There are all sorts of ways to reach 375, most require buying designs from faction vendors and crafing those to 375. Sha'tar faction will get you Design: Ring of Arcane Shielding which can take you to 365. At 370 you can get Lower City faction and buy Design: Figurine - Felsteel Boar.
Level 350-395(Northrend)
Before you get started, you're going to need a lot of gold, and I recommend you read this guide very carefully so you don't waste time. Once you're rich, buy 50-60 level 70 green quality gems off the Auction House. These include tings like Bloodstones, Chalcedony, Dark Jades, etc. Use them to craft the first trainer available recipes (there are dozens) until you're level 395. Sell these on the Auction House or dump them in your guild bank.
Level 390-425 (optional)
At level 390 you can start learning to cut blue quality gems earned by doing the daily Jewelcrafting quest. Each of these is likely to level you until level 425. You can purchase the uncut gem on the Auction House and resell it for a decent profit. Figure out which gems have the best market and markup and start buying/selling them gems and in at least a weeks time you should easily get to 425.
Level 395-400
Return to the Jewelcrafting trainer and learn one of the next 4 available crafts. Craft a total of 5 of these, any combination each requiring 1 of their respective green gems and 2 Crystallized Earth. This will get you to 400.
Level 400-420
The cheapest way to level 400-420 is to craft a total of 20-25 of: Stoneguard Bands or Shadowmight Rings. In all it will cost you a at least 40 Eternals, at least 20 Eternal Earths and a combination of 20 Earths or Shadows (for example: 30 Earths and 10 Shadows will allow you to craft 20 times). This will get you to level 420 quick. If you don't want to farm the Eternals yourself and don't have the cash, read this guide asap.
Level 420-425
By level 420 you should have several blue quality cuts that you can do. This is the cheapest way to get to 425, you can buy and sell these as mentioned in the 390-425 step above. If you don't have any of these cuts yet, you earn them by doing daily Jewelcrafting recipes.
Level 425-450
It's time to cut some meta gems. These have a decent market on the Auction House as well. Skyflare Diamond and Earthsiege Diamond are transmuted in mass while leveling Alchemy. You can find an Alchemist to transmute them or buy them pretty cheap on the Auction House. Cut them into meta gems and resell them for a profit. Recipes are available from the trainer in Dalaran. Cutting metas will get you all the way to 450.
Congratulations on level 450. Although it's been mentioned several times throughout the guide, we can't stress enough the benefit of learning EVERYTHING YOU CAN about earning gold in World of Warcraft. It really increases the level of enjoyment you get from the game.hope all of u can enjoy..