Mashed potatoes are a tasty addition to any meal, but it can be hard to gauge how much you need to make. There's nothing wrong with saving some leftover spuds if need be, and this method makes it easy to store excess mash and reheat for later.
This video from the America's Test Kitchen YouTube channel explains the best way to individually store the leftover deliciousness. Lay some parchment paper on a baking sheet and scoop out some one-cup sized portions on there. Stick that baking sheet in the freezer, let the potatoes harden up, and then store each portion in individual bags. When you're ready to reheat some, just stick a portion in a microwaveable bowl, covered, and heat until the consistency is back to normal.