When using your bathroom or kitchen sink, don't leave the water run when you don't need to. When using your washing machine, and only washing a small amount of clothes, set the water level for less water. Take the quarter inch refill tube that goes from the toilet ballcock valve into the overflow pipe in the toilet tank, and fasten it so the water from it goes into the tank and helps to fill it faster. You can only do this if when your toilet is flushed and retraps itself. While the toilet is refilling after being flushed, it doesn't take as much water as is put into the bowl from the refill tube.
Every little bit helps.
If the water pressure in your home is more than you need. Close your main water valve until your pressure slows down some, but is still enough for your needs. Or do this to the smaller valves under your kitchen and bathroom sin. A lot of homes have a lot more pressure than they need. Sometimes there are water leaks underground between your home, the street, or your outside water supply.