I usually do this:
Open with garrote, then immediatly put SnD up, after SnD use Coldblood/vendetta (I use vendetta after SnD because it would last one more GCD)
After SnD I mutilate and then garrote, then mutilate and spam envenom (if you get lucky you can just spam that because it resets SnD duration, and then all you have to do is Mutilate to reapply rupture and Mutilate everytime you don't get a proc for envenom to give 1 CP)
But I'm more into PvP, although in full pvp gear (with pve trinkets), I do about 17k dps in heroics with this rotation. (if I get lucky)
average is 15k.