Swap out lightbulbs. Choose the new energy-saving incandescent bulbs for an easy change that will use 25 percent less energy than the old incandescent bulbs. To save even more energy, switch to compact fluorescent lamps (CFLs) or light-emitting diode (LED) bulbs, which use between 70 and 80 percent less energy than traditional incandescent bulbs. Be aware that CFLs do contain a small amount of mercury, which means they must be recycled rather than thrown in the trash. See the CFL info page on the U.S. Environmental Protection Agency's (EPA's) website for more information.