1. Get a low-flow toilet installed
2. Don't flush your pee. It's sterile anyways, and if you're properly hydrated, shouldn't be yellow or smelly.
3. Use a weight in your toilet to displace water. This could be a rock, a water bottle filled with water, or something else that's heavy. Don't use bricks, as they can cause your toilet tank to deteriorate.
4. Use a toilet dam.
5. Take showers instead of baths.
6. Take short showers, or take sailor's showers (turning water on when you're rinsing, and off when you're soaping, shampooing etc)
7. Collect your rain water in a rain barrel (make sure it's covered with something that ensures mosquitoes will not breed there, like mesh). Use it to water you garden, lawn and house plants.
8. Only do full loads of laundry.
9. Make sure your dishwasher is full before you run it.
10. Turn off the tap while you're brushing your teeth or shaving.
11. Put water in a jug in your fridge instead of running the water until it's cold.