The meta gem you shall use is the 21 Agility 3% crit damage increase (Requirements: 1B 1Y 1R).Originally Posted by GaFFron
There's a Jewelcrafting Prismatic gem that gives +10 All stats http://www.wowhead.com/?item=49110 (That's all you need for your Meta gem to work).
The rotation would be Garrote, HfB, SnD, Mutilate, Envenom, Mutilate(s), Envenom, Mutilate(s), Envenom, and so on. (If you don't have somene applying a bleed effect, you need to apply Rupture once every time your HfB is about to fall off.
Professions, as I know it Jewelcrafting is the most useful to have along with Blacksmithing, however Jewelcrafting and Leatherworking (this one gave 130 AP on wrists right?) is also good.