I'm currently dual-boxing Warlocks (lvl 44) and I use one cast sequence macro on most every trash mob, it refills my life and mana to ~95% after each kill (and I regen the rest between pulls) so it is very efficient for me.

Main is Affliction and Alt is Demonology. Main has felhunter & Alt has VW for tanking.

Main Macro: /castsequence [reset=target] corruption, curse of agony, siphon life, life tap, drain life

Alt Macro: /castsequence [reset=target] corruption, curse of agony, , life tap, drain life