Instead of waiting for tap water to get cold, keep a pitcher of water in the refrigerator for drinking. New water efficient dishwashers use about 16 gallons per cycle. Running a full dishwasher is more efficient that washing the same load by hand. Run your dishwasher when it is full to make the best use of water, energy, and detergent. Cut down on the amount of rinsing you do before loading the dishwasher.
Most dishwashers do an excellent job of cleaning dishes, pots, and pans all by themselves.
Compost food or scraps or dispose of them in the garbage rather than using the garbage disposal which requires a lot of water. Wait until you have a full load of laundry before running the machine to save both energy and water. If you can't wait for a full load, use the right water level to match the size of the load. Install low-flow aerators, if you have faucets in your laundry room.