Be frugal with electricity use

Simple policy by which to live by;

If not in room, turn of the lights.
If not using computer for more than 1 hour, turn it off. Leaving your PC running all day while your at work, is firstly consuming unnecessary electricity (unless your downloading stuff), second your actually diminishing the life of the PC.
If you have speakers attached to your PC, turn it off while not using. Same goes with printer, scanner etc.
Be wary of phantom lights around the house. Phantom lights are basically standby lights notifying you, your television or DVD player is still on. These lights stay on when you happen to turn off these devices via the remote. Get into habit of turning them off from the switch on the device itself or from the main wall socket.