Bolded for importance. If you think you can be perfect on hitting BL/ME, then go manual, if not, then use a macro.
The two most used macros would be;
3in1 - you either also macro your other skills(wb,vb,ss) with ME/skill/BL or spam HS macro in between SS-WB-VB
/micon "Heavy Shot"
/ac "Misery's End" <t>
/ac "Heavy Shot" <t>
/ac "Bloodletter" <t>
BL/ME - just spam this in between GCD skills.
/micon "Blodletter"
/ac "Misery's End" <t>
/ac "Bloodletter" <t>