RE: mouth calls
The slate call will make you stop calling and get the gun up, so the bird will come the final few steps into view/range. Novice hunters tend to call too much and any bird that is close will key in on the area you called from and not seeing the hen will move off. Shut up and make him hunt for the hen. Once he starts coming, you can quit calling and wait him out, instead of calling to make him gobble. If he's coming, he's interested; he'll come....