I've set up a blind in the middle of an alfalfa field and called turkeys up to it. As long as there is no movement or unnatural sounds they won't mind the blind. Having every window open, wearing clothes that stand out against the background inside the blind, wind shifting the blind, those kinds of things will bust you.
Only open the windows that need to be, and only as far as needed. Keep the windows on the backside of the blind closed. Stay seated at the back of the blind.
