Like the guys above mentioned, good maintenance practices and driving habits will help the most. Make sure to keep all fluids, filters, and sensors in good working order, slow down, and use the cruise whenever possible. One other item I didn't see mentioned was the coolant. Make sure yours is clean and has the correct mix to keep your engine running at its optimal temperature. Each one does very little by itself, but add them all up and you should see a sizable difference.
As Stealth said it's no fun taking all of the pretty stuff off, however as greencrew pointed out pretty is getting very expensive.
