Check the manual that came with your dishwasher for the manufacturer's recommendations on water temperature; many have internal heating elements that allow you to set the water heater to a lower temperature.
Scrape off, don't rinse off, large food pieces and bones. Soaking or prewashing is generally only recommended in cases of burned-on or dried-on food.
Be sure your dishwasher is full, but not overloaded.
Don't use the "rinse hold" function on your machine for just a few soiled dishes. It uses 3 to 7 gallons of hot water each time you use it.
Let your dishes air dry. If you don't have an automatic air-dry switch, turn off the control knob after the final rinse and prop the door open a little so the dishes will dry faster.