My buddy used to toss onion skins and carrot tops without a second thought. Then his wife started a freezer bag for scraps after talking to a produce guy. She filled it with ends from onions, celery, even those mushroom stems. One rainy Sunday she threw it all in a pot with some pepper flakes. The whole apartment smelled amazing for hours, and they got like two quarts of broth for basically free. Makes you wonder what else we're just throwing away, right?