Turn of lights. This energy saving measure has been around since Edison first turned a light on, and it's as effective as ever. Keep in mind that a typical light bulb kept on 24 hours per day will cost you about $75.00 each year. Try motion sensors that turn lights off automatically when everyone leaves a room.
Keep fixtures and bulbs clean. Dirt, along with being unsightly, can absorb as much as 50% of the light.
More bulbs are not better. Use one bulb instead of multiple bulbs whenever possible. A single 100 watt incandescent bulb produces the same amount of light as two 60 watt bulbs and it uses 20% less energy.
Depends on the room. Light colored walls and surfaces reflect light while dark colors absorb light. The same light fixture in two different rooms will provide different levels of light on a reading surface.
Shades matter. Translucent lamp shades provide more light to a room than solid colored shades.
Always pull on the plug. When unplugging lights, always pull on the plug and not the cord. Over time pulling on the cord will damage it and create a hazard.
Keep lights off during the day. Use daylight whenever possible, rather than turning on redundant overhead lighting.