You don't want to be anywhere near whatever it is that has their attention. They're not going to be mystified by something and not see you move. If they're looking in your direction and you move, at all, they're going to see it. You need to get their attention somewhere that you're NOT.
You really want your decoy or bait pile, whatever, to be a good distance from you. I would guess 100 yards would be a good minimum. Considering that you should have no trouble hitting a coyote at even 250, 300 yards, I'd try to be 150-200 yards from whatever I'm using to get their attention.