Do the obvious: Don't speed. Note posted speed limits and be especially careful when coming down hills or rounding curves where speed traps may be located.
Familiarize yourself with the maximum speed limits in all the states you'll be visiting (see the Summary of State Speed Laws available at nhtsa.dot.gov). Speed limits vary from state to state and knowing them could save you a ticket.
Get on the The Speed Trap Exchange website (speedtrap.org) and find all the speed traps along your route. Take the list with you on your trip.
Buy a radar detector. It will warn you of an upcoming radar device, giving you time to slow down before you're clocked. Expect to pay between $200 and $500 for a radar detector.