Another good tip is to learn a deer's body language. For instance if a deer looks at you at close range, try not to make eye contact. A lot of times deer will look directly at you. But if you don't move and your camo is a good pattern for the area, they will seem to look through you. Remember, you're in their living room. If they put their head down, don't think all is OK. They may just jerk it right back up to see if they can catch you moving. Now if they put their head down and flick their tail - that's a sign of a relaxed deer. So just bide your time and move only when you can't see their eyes, or if they are focused on something else - another deer, passing car, etc.
Also, constantly but slowly scan the surroundings for parts of deer. It is much better to already have your bow in hand and waiting when it comes into range then to try and go through all the motions of standing, getting your bow off the hanger, drawing, etc. Getting away with all that movement means you have to move at a speed that would make a snail look fast.