For pizza, we preheat our oven at 25°F higher than the cook temperature, with the pizza stone already in there, then turn it down when we slide the pizza in. Perfectly done crust every time. Before we started doing that, we were experimenting with waiting some number of minutes after the oven said it was done preheating before putting the pizza in (as the preheat sensor doesn't know that the pizza stone takes longer to get to temperature than the air), but the high-temp preheat seems to give better and more consistent results. Our oven also beeps when it's done preheating, so no need for additional timers either!