Well, you gotta break a few eggs.

Keep the heat low so the top gets to cook before the bottom gets too crispy. Use butter in a nonstick pan. Don't try to make a 6 egg omelette in an 8" pan. Too thick and you'll be screwed. Saute ingredients separately that would have difficulty cooking 'en omelette,' like mushrooms, onions, sausage, etc. This also lets you add more flavor by way of seasonings or sauces to the filling. Don't forget to season the eggs with salt and pepper. Whisk in some cream if you're not dieting, and fresh herbs mixed in will add flavor and a nice appearance.
I once made a 'French style' one where you whip the egg whites to soft peaks and fold them into the whipped yolks and fillings, although this was more like a souffle than an omelette, as I think of it. The Spanish tortilla style omelette, heavy on potatoes, is good too, especially with a fresh salsa (good on any omelette).
An omelette pan would produce a flawless fold every time but they probably don't make 'em big enough for you monsters and who the fuck needs an omelette pan anyway.
Chopped chives make a good garnish. 'Bon Appetite, Gene.'
