I just found an article about clever uses for food scraps. My favorite suggestion was saving bits and pieces of things for making stock. Have a bag or three in your freezer dedicated to these pieces. When you collect enough, make stock. I think using animal bones for stock is common, but the ideas that caught my attention were making vegetable stock out of the ends of carrots, celery leaves, parsley stems, etc and making seafood stock out of vegetable bits and discarded shrimp tails, mussel shells and the like.
I also really liked the idea of freezing citrus rinds so that when you need some zest, you don’t have to mess up the whole fruit!