If you have only one pan and a recipe calls for more cupcakes than your pan will make, cover and refrigerate the rest of the batter while baking the first batch. Cool the pan about 15 minutes, then bake the rest of the batter, adding 1 to 2 minutes to the bake time.
Easily fill a bag with frosting by placing the bag into a mug and turning the top down over the sides. Fill with frosting, then twist to close the top of the bag, squeezing to one corner before snipping off a tip.
Bake cupcakes ahead. Tightly cover unfrosted cupcakes and freeze up to 2 months.