As others have said, it is all about playing the wind, and being still. You don't really need much of a blind, although the more concealment the better. Camoflage isn't all that important either. When a deer is in sight, you can't move unless the deer is moving,looking away, or heavily screened. If the deer is pretty close, or acting nervous, avoid eye contact, keep your face tilted down and away, and don't move a muscle.

I've been busted a few times by deer that come in pretty fast and close, take you by surprise, they stop, look, you look at them, gone. Sometimes it just happens. They live out there 24/7, and they are very in tune with their surroundings. You have to be in tune also. You have to be relaxed, calm, comfortable, blend in and become part of the scene. If you're standing there allgeeked up and vibrating, (I'm guilty of this myself sometimes) it's no wonder you get busted.