Rinse your razor in the sink. Fill the bottom of the sink with a few inches of warm water. This will rinse your blade just as well as running water, and far less wastefully. Check faucets and pipes for leaks. Even the smallest drip from a worn washer can waste 20 or more gallons a day.
Larger leaks can waste hundreds of gallons.
Use your automatic dishwasher only for full loads. Automatic dishwashers claim the most water in kitchens, about 12 gallons per load. The secret here it to make sure the washer is fully loaded before you turn it on, because it's going to use that 12 gallons no matter how many dishes are inside. Use your automatic washing machine only for full loads. Many washing machines use 40 or more gallons of water per load whether you have them stuffed full or are washing only a couple of socks.