Post by Lohr
First, you should never have to refresh SnD, envenom does that for you.
Second, your boss rotation should be garrote, HfB, SnD, Mutilate, Envenom. Then continue to Mutilate until 4+ combo points then Envenom. Keep HfB at all times (in 5 mans you may have to throw a rupture).
Third, gem AP in red sockets. Gem AP/haste is yellow sockets. Gem 1 nightmare tear in a blue socket (for meta requirement) and AP in the rest.
Fourth, keep the TotT glyph. FoK glyph isn't that great and trash doesn't really matter.
Fifth, cap hit (you are) then expertise. This means even if you have to gem for expertise.
Sixth, ideally your daggers should be slow/fast MH/OH. Instant on MH and Deadly on OH. However, always use the daggers with the highest dps even if that puts you at fast/fast.
MH/OHslow/fast - instant/deadly
slow/slow - deadly/instant
fast/slow - deadly/instant
fast/fast - deadly/instant
On the side note you want to begin your fight in stealth so you get
Overkill buff. It's huge. Occasionaly keep your eye on the boss' health and time you could even Vanish to give you the buff again and even have the chance to use Garrote for extra dps.