I usually start with straight shot , blood letter, all CDs, DoT then blunt arrow/repelling shot whenever possible between GCD and if not needed during the fight). Basically I spam heavy shot and refresh DoTs, straight shot and CDs whenever they need to/are available. Bloodletter procs are prioritized over the rest and if a straighter shot procs happen, I wait 2-3 GCD before using it, unless straight shot is about to wear off.