Bowhuntert is absolutely correct. The situation will dictate when you should draw. I like to think that if I can see the deers eyes, then they can see me. Also always try to draw on a deer thats behind something, moving, or looking away, and be wary of other deers eyes. If another deer sees you draw, she'll most likely stomp, thus alerting the other deer and put them on edge. More likely to duck the arrow.