Water pollution: Minimize the use of detergent. Consider these words about the chemicals you use. Once people appreciate that they make other things dirty when they make their clothes clean, they think differently about what they're doing.
Labor: You have better things to do than wash clothes, and you'd rather your hands didn't become dry and cracked, so you would probably choose a washing machine over hand-washing your clothes. Reducing the need for washing: Environmental impact and labor can both be saved by measures that reduce the need for washing: suitable choice of clothes (color and fabric) and habits such as hanging and airing clothes. See the Clothing page for more detailed suggestions.
Saving energy: About 90% of the energy used for washing clothes is for heating the water. There are two ways to reduce the amount of energy used for washing clothes—use less water and use cooler water. Unless you're dealing with oily stains, the warm or cold water setting on your machine will generally do a good job of cleaning your clothes. Switching your temperature setting from hot to warm can cut a load's energy use in half.