Due to European law-making, the sales of classic light bulbs has been prohibited and they have vanished from the stores. Do you still make use of classic light bulbs? Replace them with energy-saving light bulbs or LED-lamps in places which are lighted during long periods
Classic halogen bulbs are not energy-efficient. An ecological version of the halogen bulb has already been put on the market, using 30% less energy. But even more energy-efficient are the energy-saving bulbs (LED). Nowadays, they come in many formats. Their biggest advantage: they last long. So place them everywhere you often switch the lights on and off.
But after all, the best energy-saving tip we can give you remains: not using lights if not necessary. Even if they're LED.