My rule of thumb - Blind right out in the open and from my pictures you can see I place it on the fields edge "easily recognizable as you don't need to brush it in! A blind allows you to hunt areas where no sitting cover could be had!
Decoys in front of blind no more than 10-15 yards - closer if you like.
I can see anyone coming at me!
Anyone coming from behind the blind covers the decoys!
Still worried - well put a blaze orange marker on the blind itself. As long as it does not flap in the breeze it ain't gonna scare no turkey out there. But should keep the other Turkey Types away.
JW