I'm currently slowly making my way through what I assume is the tail end of the Hyjal quests; one of my current ones is The Sanctum of the Prophets. During Hyjal I've started using an adaptation of my old, TBC/WoTLK farming rotation.
First, I use the current addons:-
Kharthus Hunter Timers
I also use the following pull macro with Serpent Sting; although you'll want to swap this out with regular Serpent for instancing. This fires Serpent, but prevents a follow up autoshot, so I don't produce any additional threat. If you don't have any other mobs in the immediate vicinity, after firing, your target will go off, but immediately be reselected.
#show Serpent Sting
/cast [harm, exists] Serpent Sting
1. Measuring with Range Display, get to 35 feet of your target.
2. Drop an Immolation Trap.
3. Fire Serpent Sting.
4. Backpedal, and while doing so, send the pet when the mob hits the trap. You may get melee hit once, depending on your lag; but that is no big deal.
5. Fire Cobra Shot and Explosive Shot. I like getting the two off without an auto in between if I can, for old time's sake; I never quite got the 1:1.5 out of my system. <3
6. If you are impatient, fire Kill Shot when it lights up.
I finish with 95 focus, and 3-5 seconds left on the cooldown of Immolation Trap.