If someone in your family likes to shave with water running in the basin, they probably use at least one gallon per minute, most of it wasted. A stoppered basin needs one-half gallon or so of water for adequate razor rinsing. A faucet drip or invisible toilet leak that totals only two tablespoons a minute comes to 15 gallons a day. That's 105 gallons a week or 5,460 wasted gallons of water a year. Stop using the toilet as an ashtray or wastebasket.
Some people flush away tissues and other bits of trash in the toilet.
Using a wastebasket will save all those gallons of water that otherwise go wastefully down the drain. Most toilets installed before 1980 use 5-7 gallons of water per flush. Toilets installed between 1980 and 1993 use 3.5 gallons per flush. Toilets installed since 1994 use 1.6 gallons. In order to conserve water in your pre-1994 toilet you can install an early closing toilet flapper , which are available at participating local hardware stores.