If you know your bow is on and that you are just getting buck fever you need to take a few deep breaths and exhale slowly,also when you get a deer in for a shot you need to focus and concentrate on one spot,you need to focus on this one spot while drawing your bow and when you come to your anchor point you should still be focused on that one spot,at this point you should not be seeing anything else but that spot and you should hold that concentration through the shot and follow through.You should get you a 3-d deer and practice this pick a spot drill in your backyard,one shot one kill.You should have tunnel vision when shooting at a deer.