I think I have made every mistake possible trying to grill pizza. Here are my suggestions. Pre Heat, pre heat, pre heat, get that stone hot 500 degrees or more. I have a pizza peal that has a canvas slider that helps loading and unloading the pizza. Also use some corn meal under the pizza to act as ball bearings to help it slide. Don't over sauce or over load your pizza = soggy pizza. Smaller pizza are easier to make than big ones. Don't worry about getting it round, it ain't gonna happen. BTW you can grill directly on the grates. Grill one side pull it off, top it then grill the bottom. It won't stick I promise. Ha! Ha! have a good time.