this is a tough one to answer without seeing what the terrain looks like. could you provide any pictures of the spots you're trying to call them in from? if you have tight thick patches of bushes, you might want to invest in a decoy or make one yourself(very easy). hills can be a good thing. if you have some open terrain, set up on the top of the hill, but not at the very top. maybe like 3/4's of the way up. if you sit at the very top, the outline of your body will show on the horizon and you're screwed if they see you.

if you can, set up on the hill like i said before in a spot you can see all around you, but try and sit up against a bush so it covers behind you. if you can, sit IN a bush. call out in front and keep a careful eye out. you'll probably see a coyote hauling ass towards you from hundreds of yards away depending on the terrain out there. just make sure the wind is in your favor and make sure you use shadow as extra cover if possible. good luck man