The answer is 1. If you are not inside the mob, then you are doing it wrong. It is like food poisoning. It wreaks havoc when inside you. Same rule applies.
Seriously though, I put most of the melee toons at 10-12 in my stickhow settings and that seems to be the sweet spot for all abilities. I am not sure if it also depends on the size of the mob's hitbox either, like Dracoliches, etc.