If your pan has sloping sides, practice flipping foods without a spatula. But make sure the foods are easy to work with such as diced potatoes and sliced celery and onion for instance. Make sure your pan is greased properly before doing this. If using statinless steel, get the dry pan hot before adding any cooking oil, or lard, butter, whatever. Then add the fat, then the food. To flip, lift the pan from the burner and move it forward, away from your body. then quickly lift the pan upward while pulling slightly back, as if you were trying to use the pan to throw the food back toward you. This will in fact through the food a couple inches up and back. It doesn't take a lot of practice to get it down. At least, it came easy to me. When you are comfortable with the technique, you can use the same motion to flip an egg. You just have to use a bit more force (just a little more) to get the entire egg to flip in one piece. I turn eggs now all the time that way. It's fast and reduces the chance of breaking the egg. And once you master the skill, you will be able to use it with many foods, no an omelet though.
And Wyogal, thanks for mentioning that you lift the edges to let excess uncooked egg flow under the cooked egg part. I forgot about that technique. That's how my wife likes her omelets done, but withouth the filling cooked into the egg, but placed on top.
Personally, if I have a large cooking pan available, I prefer to gently cook the omelet, with a lid on until almost completely set, over low heat. Place the filling in the middle, from one edge to the other, escpecially the cheese so it has time to melt, and fold boith sides over the middle. Then just pick up and slide onto the plate.
I hope this helps as well.
Seeeeeeya; Goodweed of the North