Remove every shell
Never microwave an intact shell egg. Steam can also become trapped beneath an unbroken yolk membrane or inside a whole cooked egg, so break the yolk before cooking and do not reheat a whole peeled hard-boiled egg.
Use moderate power and short intervals
Microwaves create hot spots and appliances vary greatly. Use a microwave-safe dish, cover it loosely and cook at reduced power or in short bursts. Stir scrambled eggs between bursts so hot and cool areas exchange places.
Let standing time finish the centre
Stop when the egg is nearly cooked, stir if appropriate and leave it covered briefly. Heat continues moving inward during the rest. This is more reliable than one long blast, which can make the edges rubbery before the centre is ready.