If you’re taking a shower, don’t waste cold water while waiting for hot water to reach the shower head. Catch that water in a container to use on your outside plants or to flush your toilet. Saves 200 to 300 gallons a month.
Household cleaners, when dumped outside, can pollute. Always properly dispose of household cleaners and chemicals.
Drive your car onto a lawn to wash it. Rinse water can help water the grass.