Potatoes can be peeled the night before mashing them. Peeling, slicing and soaking them in cold water overnight will reduce the starch content, which is a benefit for some people. Others prefer to leave the starch in so the potatoes turn out fluffier. After being soaked, peeled potatoes should be cooked in fresh water and drained before being mashed.
Some people leave the skin on when making mashed potatoes and call them "smashed" potatoes. Others find the color of the potatoes they use enhances this dish. For example, Yukon gold potatoes have a rich, buttery hue that some people find appealing. Yukon potatoes are high in starch.