Water before 9 a.m. or after 5 p.m. and avoid watering on windy days.
Water in several short sessions rather than one long one. For example, three ten minute sessions spaced 30 minutes to an hour apart will allow your lawn to better absorb moisture than one straight 30 minute session.
Only water when your lawn is thirsty.
Over-watering promotes shallow root growth making your lawn less hardy.
To determine if your lawn needs to be watered, simply walk across the grass. If you leave footprints, it's time to water.
Install moisture sensors in each irrigation zone (sunny, shady, etc.) to better determine irrigation needs.