According to the Natural Resources Defense Council, an astounding 40 percent of food in the United States ends up in a landfill. To help cut back on food waste, try this simple tip to save leftovers at home. Invest in small, reusable flat containers with matching lids, and divide leftovers into smaller containers. This will help the food cool down faster, which prevents bacteria spores from germinating like they do in large containers. The benefit of several containers also helps with portion control, so family members can opt to reheat one container instead of an entire batch of food.