Hot water heating accounts for about 90% of your washer's energy use, so wash laundry in cold water whenever possible. Wash full loads or, if you must wash a partial load, adjust the water level. Clean your dryer's lint trap before every load, and avoid over-drying clothes. Better yet, line-dry your laundry.

Skill Level: Basic
Depending on local water quality, many homeowners can effectively wash all their clothes in cold water. Fabrics generally last longer if dried on a clothesline or rack, too.
Cost Range: Free
It's not only free to do laundry the energy-efficient way, but in hot summer months it can help you minimize indoor heat generation, decreasing the work load on your air conditioner.
Savings: $30 annually
Washing in cold water eliminates the expense of water heating and can save the average household about $30 in water-heating (with a gas water heater) every year. For extra water and energy savings, wait for full loads to do the washing.