Defrost frozen foods in the refrigerator or naturally thaw foods before cooking to reduce cooking time. Use your oven light and inspect food through the window of the oven door, instead of opening the overt door as you cook. Match the burner size to the size of the pan. Keep range-top burners and reflectors clean. Don't lay foil on oven racks.
Foods cook more quickly and efficiently when air can circulate freely.
Consider using a microwave, toaster oven or crock pot when cooking small to medium-sized meals. Turn off lights in unused rooms. Take advantage of natural daylighting. Compact fluorescents are good replacements for outdoor lighting. Time clocks and motion sensors automatically turn off lights when you leave a room.