Wash only when dirty. Most pants and some shirts can be worn two to three times before washing.
Line dry clothes year round. A large drying rack will make this easy and convenient. The U.S. Department of Energy rates clothes dryers as the second biggest user of household energy.
Buy concentrated laundry detergent in refillable containers. This cuts down on shipping weight and garbage.
Use non-chlorine bleach to keep whites white. Chlorine bleach is a lung and eye irritant. It also kills beneficial bacteria and is not recommended for home septic systems.
When purchasing a washer, choose Energy Star appliances which use significantly less water and electricity than standard washers.