What's that you say? I can save energy by being smart? Well, yeah you can. And it won't cost you a dime.
Leaving the room? Turn off the light, the tv, the radio, the computer, or anything else plugged in that is consuming power.
Going to bed? Adjust the thermostat a bit, you don't need or want the temperature to be 70 degrees at night. Thats what blankets are for.
Use your head and some common sense, you will be great after its all said and done.