Make sure every water shut-off valve is operational. The worst time to discover that they are not working is when you need them. Do you have a lever-controlled shutoff? Or is it a round one? Some types of shutoffs deteriorate from the inside. This occurs when you turn or twist the handle and it moves properly but the inside operation of the valve has gone bad. You should always double check to make sure the water is turned off. Test your shut offs on a regular basis to make sure they turn the water off completely.
Check the discharge hoses from dishwashers, washing machines, ice machines, water filters and reverse osmosis systems. The tubing can crack and develop slow leaks that turn into bigger problems. Catch minor leaks before you have a deluge.
Replace fixture washers as soon as you notice a leak. Turn the water off at the fixture, and then remove the faucet handle. The washer is dark, round and flat, and it sits under the handle to make sure the handle has a tight grip around the shutoff post within the faucet. If the washer looks worn, it is time to replace it.
Take a look at the base of your toilet. Does water seem to build up between the floor and the toilet? It may be time to get a new wax ring. The ring sits between the toilet base and the floor, creating a tight seal. Use the shutoff valves to turn the water supply off and then drain the water from the toilet bowl. Flush the toilet to drain the tank and then empty the bowl again. Remove the fastening caps from the base and unscrew the bolts. Lift the toilet from the floor and examine the wax ring. If it is very thin or worn in spots, replace it.