I hunt public land exclusively. One of the things you see a lot is multiple hunters on one bird. The first thing ALL hunters should do is respect others that are hunting in an area. If someone is parked in an area, don't park next to them if you don't know where they are. And don't try to figure out how you can get to the same area by coming in from a different direction.

If you are setup on a bird and you hear another hunter calling or coming to the bird you are on, give three distinct yelps to let them know you are there. It happened to me last year where another hunter was coming in off a ridge blowing a crow call getting the bird I was watching to gobble. I gave him three loud yelps (had to do it 3 different times) before getting his attention. The gobbler was only about 100 yards from me and was in sight. It never spooked the birds but it let the hunter know I was there.