If you’re freezing vegetables, a technique called blanching — a fast dip in boiling water and an equally fast cool-down in cold water — before you freeze them helps preserves their color and taste (dry them thoroughly before freezing to avoid ice crystals).
Before refrigerating or freezing leftovers and other foods, place them in shallow containers for faster cooling or freezing. The USDA advises throwing out any cooked foods that have been at room temperature for more than two hours, and after one hour if the room was over 90 degrees Fahrenheit because bacteria will have had time to develop.
Keeping your fridge and freezer compartments clean helps keep food safe, too. Wipe up spills immediately. Once a week, throw out older perishable foods even if you think they look okay.