I use a box or slate call. Do yelp calls until you hear one gooble. Then a few soft calls, then shut up. The tom will know exactly where you're at and come walking right in.
Don't use a decoy in the morning but i do use a single hen in the afternoon in a small clearing. This way the can see there's a hen waiting for him after he been called at all moring long from other hunters. It works every time for me.