If you see another hunter sneaking up on you decoys, yell "DECOY!!" and don't move. On the same vein, set your decoys so you can see a long ways behind them (i.e., further than a shotgun can shoot). Always remember, you are wearing full camo and making noises like the thing that everyone out there is hunting (be extra careful with a gobbler call on public land -- I leave mine at home.