1. Because higher fees and taxes are charged at airports, it is often cheaper to take a shuttle into a city and rent your car there.
2.Call the local rental agency directly. You can negotiate the cost better with people who know their car inventory.
3. Use your digital camera or phone (with date and time activated, if possible) to show the dings and dents to the rental agent prior to your use (get his/her full name).
4. Know the refuel policy so you can decide which is cheaper--paying upfront or refueling it yourself.
5. Saturday is generally the cheapest day to rent for one day.
6. Watch rental prices (they can fluctuate many times during the same day!!). Even though you may have a reservation, you may be able to get an even lower price. Check prices online and if they are lower, speak to the local rental agent.
Find out if you are too old to rent a car and how to prepare for car trips at this website.