In the kitchen

• only run the dishwasher with a full load
• scrape your dishes clean instead of rinsing them before washing
• place a stopper in the sink to wash pots and pans, rather than turning on faucet each time a rinse is needed

In the bathroom

• when brushing your teeth, turn off the faucet until it is time to rinse
• take showers instead of baths; showers with low-flow showerheads (install one!) often use less water than baths

In the laundry

• wash only a full load when using an automatic washing machine
• use the lowest possible water level setting on the washing machine
• use cold water as often as possible

Outdoors

• water lawns early in the morning or late at night to avoid evaporation, & avoid watering lawns in windy weather
• use a broom rather than the hose to "sweep" walks and driveways
• use a bucket of soapy water to wash your car and save the hose for rinsing

Sources:
American Water
This Land
Save Texas Water