I lowered my bill at least 25-30% by using some of the same tactics that others have mentioned:
1. Displace some water in the toilet tank with a brick or water-filled milk bottle (I don't leave contents unflushed);
2. Shower at gym or pool when possible, or shower only every other day when not really dirty. I sponge bath on the alternate day;
3. Catch water in the kitchen sink to use for pre-rinsing dishes;
4. Use low-flow showerhead and faucet aerators. A new kind allow you to temporarily turn off the faucet while soaping or brushing teeth, then flip it to turn it on again, thereby not getting the faucet dirty;
5. Use indigenous plants in the yard that do not require extra watering during dry spells;
6. Skip car washing;
7. Catch cold water from warm water pipes (but don't drink it, it may have harmful metals from your pipes); use it to water indoor plants, rinse dishes, etc.;
8. Use water level adjustments on clothes washer, but try to do full loads to save electricity;
9. Take short showers, not baths;
10. Encourage others to do the same.
There are water conservation sites online that have more tips.
Sunny