Plan your meals, use a shopping list, and avoid impulse purchases at the grocery store. Brown-bag your leftovers for tomorrow’s lunch or freeze them for use at a later meal. Store cereal and other grain-based products in airtight containers. Use slightly wilted produce in smoothies, soups, or stews. And don’t automatically toss food just because it’s reached its expiration date; many foods are perfectly fine to eat even several days past that date.