Flush only when necessary. Don't use the toilet to dispose of cigarette butts or other trash.
Repair leaks. Add food coloring to the toilet tank water, and check the bowl in 15 minutes. (Don't flush.) Color in the toilet bowl probably means there's a leak.
Sink
Plug the drain and use only as much water as you need to wash or shave.
Don't let water run when you brush your teeth.
Repair leaks or drips.
Tub or shower Plug the drain before you run water for baths. Take shallow baths and keep showers short.
Water-saving devices are available for the toilet and shower.
In the kitchen:
Sink
Check the faucets and pipes for leaks.
Replace washers, and repair or replace fixtures if necessary.
Install an aerator or flow restrictor in the faucet.
Dish washing
Scrape dishes, but don't prerinse.
Soak pots and pans before washing.
Don't keep the water running. Plug the wash and rinse basins. Use only as much water as you need.
Use only as much detergent as needed.
Run the dishwasher only when it's full.
Inspect all connections to the dishwasher, and repair any leaks.
When doing laundry:
Use the load selector. Match the water level to the load size, or do only full loads.