A pan and a splash of water works.

Use a skillet, not the microwave.

The microwave nukes spaghetti unevenly: ends up dry and rubbery in spots, cold in others. A pan gives you control.

Put the leftover spaghetti in a nonstick skillet over medium heat. Add a splash of water—like a tablespoon—or a spoonful of leftover sauce if you have it. Cover with a lid.

Let it steam for about a minute. Then uncover, stir, and let any excess moisture cook off. The steam rehydrates the pasta without making it soggy. If you want a little char or crisp edge, leave it uncovered a bit longer.

Works for any long pasta. Just don’t crank the heat—medium is fine.

Microwave is for people who hate their future self.