you can wash out and reuse the little plastic tub containers that things like yogurt and cottage cheese come in and if you like, you can remove the ink labeling with a cloth or paper towel, 100% acetone nail polish remover, and a little bit of elbow grease I’m really excited about getting free containers
I generally wash out things like takeout containers and reuse them.
Though I try to be careful to not use them for excessively hot foods. Which means not microwaving them, among other things.
I’ve also found that grease on plastic is particularly annoying to wash off, so I try to avoid using them with foods that are too greasy.
FWIW they can be useful as non-food storage of various trinkets, as well as plant pots and plant pot dishes, even they can’t be used for food.