Ill lay it out nice and simple:
BEFORE YOU START THIS GUIDE MAKE SURE YOU HAVE A HIGH LVL OF JC/ENCHANTING OR YOU WONT BE ABLE TO MAKE/DE THESE ITEMS
1. Go buy the pattern for Braided Eternium Chain on the AH. Thottbot World of Warcraft: Design: Braided Eternium Chain
2. Buy/Farm the mats for it (As many as you can afford, because the more u get the more u can DE)
3. DE them all (most of them will be Large Prismatics but perhaps the occasional Void Crystral)
4. Sell on AH.
P.S. Don't post too many at once, you want to keep the demand high, put a couple on AH then try sell the rest in trade.