#7. Don't Play With Your Food
My girls used to watch the movie Lion King repeatedly when they were little, and there was a line in it when Zazu says to Scar, "Didn't your mother ever tell you not to play with your food?"
It's true regarding grilling and a mistake many home cooks make. They can't help themselves from constantly fiddling with what they are cooking - moving food around, poking it, flipping it, pressing down on it.
What gives most foods you grill so much flavor is the caramelization that takes place when the food is seared and left alone.
Of course, you have to flip what you are cooking at least once to cook both sides and if you use the two-zone technique mentioned previously, you'll move the food again but try to resist the urge to give it a poke or constantly flip. Instead, let it develop the wonderful flavors available from grilling.