Did you know that the reason the Chinese take out boxes are shaped the way they are is because they are meant to be used as plates?
I never knew!
This page contains the following solutions.
I save most of the better take-home containers we get from eating out at restaurants, some are quite sturdy. Whenever any of my married kids comes over for a meal at my house, I'll usually send some leftovers home with them for their lunch the next day.
Anytime I go to a restaurant and take the rest of my food to-go, I keep the boxes, wash and dry them, and save them for the holidays when friends and family come over.
Whenever you get one of those clear acrylic, clam-shell type to-go food containers, especially the smaller ones, wash them out and save them.
My local grocer has wonderful soup, we sometimes buy 3 a week. They come in a 2 cup Styrofoam container with plastic lid. I've been recycling them and use as leftover containers.
My sister-in-law did something for Christmas that we all thought was smart. She saved the containers in which she had purchased take-out food all year. It was easy to just grab and fill them from the left-overs.
I reuse the plastic container that hot whole chickens come in from the deli. I mix up all the ingredients for a big meatloaf, press into the plastic dome, then dump pressed meatloaf mixture onto a broiling pan; to drain grease when cooking.
I always have a supply of the plastic containers delis and Chinese restaurants use. When I have guests over for meals and want to give them a "care package," I don't have to ask them to return the container.
About once a week we have delivery meals. Most of the time we end up with 1-2 small clear containers with lids. I use these for pouring small amounts of paint, glue, water, and even smaller amounts of loose beads.
I save and wash deli containers (the kind potato salad comes in). I use them to send "squishable" stuff like brownies and cookies with lunches to keep them from being smashed, and if I don't get them back, not a big deal.
