Clean the driveway with a broom, not a hose
Instead of hosing down your driveway, sweep it off. By using water to clean it, you not only use up good drinking water, you also send contaminants such as oil, fertilizers, pesticides, detergents into the environment and the storm drain.
Replace high-flush flush toilets with a high-efficiency toilet (HET) that uses 1.28 gallons per flush to save up to 4,000 gallons of water per year. If you don't want to make a capital investment, you can put a bag of air in the tank to minimize water volume (check the local hardware store).
Your toilet may have a leak and you may not even know it. Drop about six drops of red, blue, or green food dye into the tank of the toilet and wait an hour or so. Come back and see if the bowl has changed color. If you see any color, your toilet is leaking water, wasting countless gallons of H2O annually. Call a plumber and get it fixed.