How a pro does it:
Chop all the veggies/meats that you want in the omelette and place in a small bowl. Crack and scramble 2 or 3 eggs in a coffee mug.
Heat a saute pan over med-high heat. Add a tablespoon of clarified butter. I actually cut the butter with a bit of canola oil at home. Add the veggies/meats, and a little pepper. If you have hame, bacon, or sausage, I wouldn't add any salt. Saute the goodies for a couple of minutes, or until the onions (if there are any) begin to turn translucent.
Add the egg. I find it best to pour the egg in slowly, in a ring around the edge of the pan, then pour the remaining egg into the center. Shake and/or swirl the pan to ensure that the egg completely coveres the bottom of the pan. Cook until the egg begins to congeal and solidify. Carefully lift up the edges of the omelette and let the liquid egg run under the cooked egg.
When there is hardly any liquid egg left, swirl the omelette to make sure that it isn't sticking anywhere. Flip the omelette (yes, I actually do toss it up and catch it with the pan). Place the back on the burner, turn off the heat, and top with cheese, if desired. 30 seconds later, plate the omelette. I usually fold it in half with the pan edge as it slides out of the pan, but sometimes I can actually get it to roll up.
Flipping the omelette, and plating the way I do, are acquired skills that take time to learn. You will probably want to use a spatula to do this.