In most homes, about 10-15% of the electricity bill is for lighting so energy saving light bulbs can cut your costs considerably. Traditional bulbs waste a lot of energy by turning it into heat but energy saving bulbs work in the same way as fluorescent lights, the tubes coating glows brightly as an electric current passed through gas in the tube.
They may be more expensive to buy than traditional bulbs, but they are worth the investment as last over 10 times longer and use up to 4 times less energy. Where you would use a 100w ordinary bulb, you would only need a 20-25w energy saving bulb. With savings like this, changing bulbs throughout your house could really cut your electricity costs.
No matter what type of lighting you are using, always turn the lights off when you leave a room.