You can buy fruit already frozen or you can wash and prep fresh produce that may go bad before you can eat it. Simply wash it well and prep as if you'd be eating it (ex: remove stems and any seeds necessary). Then dry well and lay flat on a sheet to freeze for a bit in the freezer. Once it begins to harden, you can combine them all in a freezer-safe container to store until you're ready to use. If you don't freeze flat first, then they may end up all clumping together.