Exterior lighting is one of the best places to use candescent florescent lamps because of their long life. If you live in a cold climate, be sure to buy a lamp with a cold-weather ballast.
Turn off lights that are not needed, like in unused rooms.
Replace incandescent light bulbs with new, energy-efficient compact fluorescent lights.
Replace all bulbs with lowest acceptable wattages.
Use timers or motion detectors on lamps that are used for security lighting.
Use natural daylight as much as possible.
When possible, use one large bulb rather than several smaller ones.
Clean your light bulbs regularly, since dirt diffuses light, decreasing illumination.