Write the next sentence in this paragraph:

How to double dip travel rewards
Enroll in a frequent flyer program that makes sense for you.
The most common type of travel rewards are airline miles. In order to earn the most miles, including in double-dip scenarios, you'll need to join a a frequent flyer program that you will be most able to use.
For many people, this is simply the program affiliated with whatever airline they fly with most often. One factor is proximity to an airline's hub.