Since the expansion, I've made over 26000g by just crafting and disenchanting Stoneguard Bands
I'm sure I'll be making a lot more gold with this forgotten technique
I did a quick search the the threads for this trick were over 2 years old, and since there's a "No Bumping Old Threads" rule, I just decided to bring back this hidden gem of a trick!
Here's what you do:
1) Buy all Eternal Earth off your AH. They should be really cheap now since the demand for them is so low with Cataclysm here.
2) Craft Stoneguard Bands with all the Eternal Earth you just bought. (Requires 400 in JC)
3) Disenchant all of the Stoneguard Bands into Infinite Dust and Greater Cosmic Essence
4) Sell the Infinite Dust and Greater Cosmic Essence back on the AH for 200%-500% profit!
The demand for Infinite Dust and Greater Cosmic Essence right now is still very high, as a lot of players are leveling new Goblins and Worgens, or new class/race combinations (which means they'll be leveling professions as well).
Enchanting has and will always be one of the desired professions, so the demand for these will always exist!
Good luck!