For starters how far are you shooting at these deer? Limit yourself to a 20 yardbroadside shot until you've bagged a few.

Also, are you getting real bad buck fever? Alot of times guys will "forget to aim" in the heat of the moment. They're just flinging arrows. Relax, take your time and most of all PICK YOUR SPOT on the deer. Remember to follow through. Don't watch the deer, watch the SPOT your aiming at until the arrow hits. You're probably dropping your bow arm and looking to see where the arrow hit.

Also, if you don't already I'd suggest using a peep sight. Without a peep it's too easy to come to the wrong knock point in the heat of the moment, especially with a facemask on.