In many areas of the country, efficiency in how water is used is extremely important. Water restrictions are commonly used in arid regions to limit how much water can be used and what it can be used for. These sometimes limit or ban watering lawns and washing cars. Even where water restrictions are not an issue, it makes sense to use water wisely. Here are some tips to help you conserve this vital liquid resource. 
Go low flow - Look for low flow options when it comes to faucets and shower heads. These significantly reduce the amount of water used and by using various techniques to increase pressure, especially with shower heads, the effect is unnoticeable. This will reduce the gallons per minutes (gpm) from about 3.5 to 2. Low flow faucets can use up to 2.5 gpm less. In either case, the amount saved is dependent upon your home's water pressure.
Low flow means less hot water - A secondary benefit of low flow fixturing is a corresponding reduction in the use of hot water. Less used = less to replace, saving energy.
Use timers and rain sensors - When watering your lawn, either with sprinklers or an in-ground system, be sure to have a reliable timer and a rain sensor. The latter prevents the sprinkler from operating while it is raining.
Low flow toilets - These alternatives use about 1.6 gallons per flush (gpf) compared to the 7 gpf of standard toilets.
Convert traditional toilets to lower flow - An old recommendation from the 1970s was to reduce the amount of water used per flush by putting a brick in the toilet's tank. It can be effective, but care must be taken to not damage the tank mechanisms or the tank itself.
An alternative is to adjust the float in the tank so it shuts off the fill valve earlier.
Leaks or water waste can occur in toilets at a couple of key spots you may not notice. One is the flap seal in the tank. It is raised by the lever when you press the handle and it falls back down after the tank is emptied. Over time, deposits can build up around the opening and the material of the flap degrades. Check, clean, or replace if you hear water running or if you notice it running in the bowl after the fill valve turns off.
The other is the fill valve itself. Like the flap, the materials can degrade, and the valve can stick in a partially open position. Check, clean, or replace if the toilet won't stop running.
Find and fix drips and leaks - Anything that drips or leaks is wasting water. Fix faucets. According to the United States Geological Survey (USGS), it takes 15,140 drips to waste a gallon of water. That doesn't seem like much of a waste, but let's do some math:
10 drips per minute x 1,440 minutes per day = 14,400 drips or nearly a gallon. (https://water.usgs.gov/edu/activity-drip.html)
Reduce water use by:
- Taking shorter showers
- Run dishwashers and washing machines with full loads only
- Collecting rainwater for landscape watering
- Turn off the faucet while brushing your teeth