Replace old heating/cooling equipment and major appliances with high-efficiency models.
Many devices are far more energy efficient today than those made just a few years ago.
Look for the seal that indicates an Energy Star recommended product.
Use blinds or drapes to help regulate indoor temperatures. Open them on sunny winter days to let warmth in; close them on hot summer days to keep cool air in.
Close the damper on your fireplace when not in use.
Lower your thermostat in winter; raise it when using air conditioning.
Lower the thermostat on your hot water heater.
Install programmable thermostats.
Install a hot water recirculation system.
Use ceiling fans to improve air/heat distribution.
Fix leaky faucets.
Install low-flow shower heads.
Turn off appliances, TV's, computers, etc., when not in use.
Replace conventional light bulbs with compact fluorescent bulbs.