Mix up the eggs and milk in a bowl. You can skip the milk, but it adds the fluffiness to your eggs that is the trademark of a good omelet.
Pour the egg mixture into the skillet and swirl it around so it coats the pan thoroughly. Add salt and pepper.
Gather your fillings into a bowl. The amount of filling is a personal matter, so use as much or as little as you like
Watch your omelet. When it's setting up so you can see a lot of the egg whites cooked, give the pan a second swirl. Swirling as you cook the omelet allows for easy flipping, so don't forget this step.
Allow the omelet to cook until the crispy edges begin to peel away from the skillet. Add your fillings by placing them on half the omelet face.
Run your fork under the portion of the omelet that has pulled away from the edges of the pan. Using the fork or your spatula, gently fold the portion you just loosened over the top of your filling. Let it cook another 30 to 60 seconds, then gently slide your omelet onto a plate.