After rolling the meatball mixture into 1-inch balls, place them on a baking sheet lined with parchment paper or aluminum foil. Ensure they are not touching each other, then place the baking sheet in the freezer until the meatballs are frozen solid. Once frozen, transfer the frozen meatballs to a freezer bag or container, removing as much air as possible before sealing. Allow the cooked meatballs to cool completely before transferring them to a freezer-safe container or freezer bag. Ensure they are arranged in a single layer to prevent them from sticking together. Seal the container or bag, removing excess air and store in the freezer for up to 3 months.