Not using a non-stick pan
The debate over nonstick vs. cast iron vs. stainless steel pans is never-ending. When it comes to cooking eggs, the choice is simple: use a nonstick pan. If an egg becomes stuck in the pan, it may break. Though not ideal for searing, a nonstick pan will allow your fried eggs to easily slide around on the pan's nonstick surface.
Cleanly cooked eggs should come out of the pan. Nonstick pans, for better or worse, give eggs the best chance of succeeding. While you may not use a nonstick pan for all of your cooking, they are a must when it comes to eggs. Other pans, such as stainless steel or cast iron, may cause sticking, though this is debatable in the cooking world.