After the dots are applied you just spam "Heavy Shot" and use "Bloodletter" whenever it's off cooldown, important that you always keep your "Straight Shot" buff up, reapply your dots, and be ready for whenever your buffs are off cooldown aswell. You should always try to apply dots whenever you pop your "Internal Release" and this is ofcourse for it's 20% crit chance along with your 10% from "Straight Shot" like i mentioned earlier. other than that there is not much to it.

Quelling Strike-->Straight Shot-->Bloodletter-->Internal Release-->Windbite-->"Buff" (i.e Raging Strike)-->Venomous Strike-->"Buff"-->Heavy Shot-->"Buff"--> Heavy Shot/Bloodletter-->"Buff".

And yeah like I said, worth mentioning due to the importance:

1. Keep Straight Shot buff up at all times
2. Keep your dots up and always reapply if you pop "Internal Release"
3. Use your "Bloodletters" as soon as they are off cooldown