Above all else.. Get plenty of sleep the two days before the hunt. Nothing else will bother me more than being tired and fatigued while trying to sit all day. The exhaustion will work on you until you are convinced that no deer are coming and it is worthless to stay. As soon as you get home you regret leaving and your mind starts to convince you that a monster just walked under your tree. AAHHHH, SILLY TORTUOUS GAMES!
Try to take a BIG crap before you go, that's a good tip.