After picking fruit, come home and make pie filling. Mix up each batch and place each pie filling in its own freezer bag. Then place each freezer bag in a pie pan and place it in the freezer to freeze in that shape. Once the filling is frozen, take it out of the pan and store the fillings in stacks in the freezer. When you want to make a pie, unwrap a filling, plunk it into a crust, and bake!