at level 25, its hard to say. from what i recalled, i usually opened with life leech. since this is a bolt spell, I would begin casting a VB or PB (whatever ur spec'd into) while the life leech is on its way to the enemy. After that, I cast my dots (necrosis, dark touch) then I soul purge to finish off the mob. At level 50, I usually just pull every mob in sight for my dailies by dotting them up 1-2, slap down graverot AoE, then I use that warlock skill that is an AoE damage heal which is pretty beast for PvE. By that time my pet usually has one mob down, and i just finish off the rest however.