Check that new hose washers are installed in the female ends of all of your garden hoses to ensure a good seal with hose bibbs and that the attachments that you connect to your hose also have new washers to properly seal to the male end of your hoses. Leaks in the hose or misshapen hose ends that have been bent need to be repaired or the hose should be replaced. Good garden hoses are available at most garden centers for a reasonable price. You will get years of use from a good rubber garden hose instead of those silly, vinyl snake skin looking things. Well-maintained hoses are a good water saving device.
Irrigation systems are such wonderful labor saving devices.
But we seem to think that the garden isn't properly watered until we see our precious resources running down the street in the gutters. This is not true. It is a good idea to go out into the garden when the irrigation system is on to check that all of the sprinklers are facing in the correct direction. This is also a good opportunity to check that each sprinkler is working correctly and hasn't been damaged by the lawn mower or some other act of God. A leaky sprinkler can cost a thousand gallons of water a month.