Use your cloths dryer less. Hang your clothes to dry. Wash and Dry only full loads.
Unplug all those small wall transformers that are not is use. The ones you use to charge your cell phone cameras, and such. They all use small amounts of electricity when even when not being used. Feel the warmer they are the more electricity they are using.
Turn off your lights.
Replace all your incandescent lights with lower power fluorescent bulbs. They generate less heat and use electricity. This will also cut down on the cooling bill in the summer.
Get a timer for your hot water heater to shut it off at night and when your not at home. Your water heater is constantly working and using energy to heat the water to the set temperature, even when you are not at home or on vacation.
Turn your computer off when it is not being used. Consider cutting it off at the power strip if you have lots of other devices attached. If there are any transformers attached they generate heat(and use electricity) even when the device they power is off.
Set your thermostat a little higher than normal. Try using your ceiling fans or regular fans to help circulate the air.
Use your stove less. This may not be practical all the time. Stoves use a lot of electricity. In the summer the increase in heat will cause your air conditioner to work harder than it needs to.
Change you air filters. A dirty air filter will cause your heating/cooling system to have to run much longer. Your system will have to work harder to force air through a dirty filter. Check them every 3-6 months and see if they need to be replaced.
Use you windows and Drapes effectively. On cold day open the drapes so that the sun can shine in to help heat the house. On warm days pull the draped so your conditioning will be more effective. Also consider upgrading your windows to a double pane unit with low e glass. This will help with energy efficiency.