Wash clothes & dishes only when you have full loads. Also, scrape off the food scraps instead of rinsing each dish before you load it.
Washer: saves 15–45 gallons per load*
Dishwasher: saves 5–15 gallons per load*
Washing by hand? Kitchen faucets can spew about 2 to 5 gallons of water per minute. If you're letting your faucet run the entire time while you're washing dishes, you've already used the same amount of water as a dishwasher after approximately 2 minutes. Instead of letting the water run, fill the sink no more than half full with water and detergent, turn off the tap, and wash a stack of dishes at a time. Don't drain or refill the sink unless the water becomes cold or dirty. Rinse your dishes in standing water.
*ENERGY STAR-rated appliances