Here's how to freeze strawberries, before the fresh ones you have on hand spoil. They make a great smoothie ingredient, and are also perfect for making jams and desserts.
Rinse the strawberries to remove and dirt, and pat them dry with a towel. Slice the hulls (green leaves) off the top with a knife. Line a large baking sheet with parchment paper.
You can freeze strawberries whole, or sliced in half. I like to slice them in half so that they will blend easier in smoothies later. Arrange the strawberries in a single layer on the lined baking sheet. (I arrange them cut-side down.)
Place the pan of strawberries in a freezer to freeze until firm, at least 2 hours. Once the strawberries are frozen solid, you can transfer them to an airtight storage bag or container with a lid. They will be individually frozen, rather than stuck in a big clump, so they will be easy to measure for recipes later!
Frozen strawberries can be stored in the freezer for up to 6 months. (Possibly even longer, but they may start to lose their flavor.)
Notes
You can use this method for freezing any other berries, too! You won't need to cut raspberries or blueberries in half before freezing, so the process is even faster.