A bath in a partially filled tub uses less water than all but the shortest showers. Turn off the water while you brush your teeth. Rinse your razor in the sink. Check faucets and pipes for leaks. Even the smallest drip from a worn washer can waste twenty or more gallons a day.
Larger leaks can waste hundreds.
Use your washing machine only for full loads. If you wash dishes by hand, don't leave the water running for rinsing. Don't let the faucet run while you clean vegetables. Keep a bottle of drinking water in the refrigerator. Check faucets and pipes for leaks.