I used to use the skillet method where you drop some water next to it and cover it, so you get crispy crust and melty cheese. But honestly, lately I just throw it into the air fryer.
I put the pizza on a few paper towels (on a plate), sprinkle a little water on the pizza, and reheat it in the microwave for maybe 20 or 25 seconds (or as needed). It always comes out fine.
Usually I eat it cold, but the other night, I microwaved for a few seconds to soften through, then put in a pan (covered) on low heat for a few minutes. Texture and flavor was great
The proper way to eat leftover pizza the next day is to wake up on the floor, see the box still sitting next to you on that floor, and reaching in to take a piece to eat it on the spot as breakfast without moving from your floor spot.
Put pizza in cold oven on baking sheet, then set the temp to 350. Once it comes to temp, let it go for an additional 2 - 4 minutes depending on your preference. Comes out perfect every time.
I've tried the water-in-a-covered-skillet trick once or twice, but it's never really worked for me. I'm probably using too much heat; seems like I always burn the bottom before the cheese gets melty. And then I don't get to enjoy the goodness that is cold pizza.
This is how we reheated pizzas at an actual pizza joint I worked at in college.
You can also slide it into an oven at 375F for four or five minutes. Most people won't notice the crust being slightly more dry than when using the above method.