Don't pre-rinse dishes

Air bubbles trapped in ice, Canada
Photograph by Philippe Bourseiller

Your dishwasher will use the same amount of water and energy whether or not you pre-rinse your dishes. In most cased, simply scraping off food scraps should be enough for your dishwasher to do its job, especially if it is an updated model. Pre-rinsing can waste up to 20 gallons of water.

If certain types of dishes or foods prove problematic for your dishwasher, set aside a small amount of dishes to wash by hand - fill up the sink basin rather than let the tap run while you wash. Otherwise, let the dishwasher do all the work.

-from the book '365 Ways to Save the Earth' by Philippe Bourseiller