Aside from practice, to make a classic omelette you need some idea of what you're attempting to do. Creamy omelettes live at the intersection of romance, tradition and simplicity. From SeriousEats, we get the romance, as well as a new idea to keep your nonstick pans intact. From Jaques Pepin, we learn the traditional methods from a master. Understand exactly what you're making--soft French-style scrambled eggs left to sit in the pan without moving to form a skin, then rolled to hold it all together in a delicate, quivering quenelle--and it's the simplest thing in the world to throw together any morning of the week. It's perfectly acceptable for lunch and dinner as well, and all on the same day.
I'll admit, it was this SeriousEats article that started me down the path of wanting to make a classic omelette.
On its own, though, that article didn't have all the answers. The next step of discovery was to see a master at work. You get a couple of extra tidbits that made the omelette game easier. Shake the pan while whisking the egg. Instead of rolling the whole omelette like a pancake, pool it at the edge of the pan before you let it form that final outer skin. Whack the handle to coax the egg to roll back on itself. Grab the pan handle backhand, and tilt onto the plate. You end up with a pool of custard eggs barely contained by a delicate shell.
Here, Pépin explains more about omelettes, rounding out your eggy education.
It's basically French scrambled eggs in a slightly-cooked egg shell.
Gordon Ramsay's explanation, which is how I first discovered the custardy curds.
To be really spoiled, pair French scrambled eggs with some duxelles (dook-sells). Both are creamy, sensuous celebrations of simple ingredients.
Combine those sources, along with a few dozen eggs, and you'll be able to enjoy cheap, fast, and decadent breakfasts.