Insulate and weatherstrip. Close doors to rooms that you don't use. And don't heat or cool them.
Take quick showers. They use less hot water than baths.
Wash clothes in cold water. Then you don't use energy to make hot water.
When it is time to buy new appliances, buy fuel-efficient models.
Run dishwashers and washing machines only when there is a full load. Hang clothes outside to dry instead of using a clothes dryer.
Hang clothes outside to dry instead of using a clothes dryer. Hang clothes outside to dry instead of using a clothes dryer.
Recycle everything you can (paper, glass, metal cans, aluminum and plastic). It takes less energy to recycle these things than it does to make new ones.
Turn off lights and appliances you are not using. Use fluorescent lights instead of incandescent bulbs.