Cover the food with paper! First, some safety stuff (or you can skip this and just use wax paper, which is safe):
Be warned that there might be some safety hazard. I have used this my entire life without any problems, but that doesn't mean that problems won't crop up.
- Make sure you don't have metal in the microwave. You don't want sparks to set fire to your paper.
- Paper burns at 451 degrees Fahrenheit. Food in a microwave rarely gets above 212 degrees. So the paper should not catch fire
- "Most paper plates, towels, napkins and bags [are microwave safe]. For optimal safety, use white, unprinted materials." ref So unprinted printer paper would likely be okay. However, note that "brown paper bags and newspapers" same ref are not microwave safe.
- More things supporting microwave safe:
- More safety to keep into account:
- This says the chemicals from paper can transfer to your food.
I didn't find much that specifically talked about printer paper, but you might want to play it safe. Printer ink isn't too good to ingest, but if you don't care about that, you can use old printed paper. If you do care, you could use one-sided printed paper. Or you could just use paper.
If you want more safety, wax paper is completely safe, as can be seen from various references.
Now that safety is out of the way:
For something like a bowl, just lay the paper directly on top if it's not going to touch your food anyways. If your microwave has a tray that rotates, you might have to fold the ends down so that the paper doesn't get pushed off.
For something like a plate, fold the ends down to give the paper some elevation, and fold the center of the paper so it doesn't touch your food much. If you do mind the paper touching your food, you might have to add some supporting folds the other direction. Something like this: