Q: What are strategies for earning the most miles by flying?
A: As much as possible, concentrate your earnings into a single program. If you earn 25,000 miles in one program during one year, you will earn both elite status in that program and a free award ticket. If you spread those same miles among several programs, you will earn neither elite status nor a free ticket.
Take advantage of bonus mile offers whenever they are available. Typically, these promotions provide extra miles on certain routes for a limited time period, or they may grant additional miles to travelers for long-haul flights. See SmarterTravel.com's Mile Finder for current bonus offers.
Use a mileage-earning credit card to buy your airline tickets. That way you get miles both for purchasing and for flying.
Be sure your earned miles are properly credited. Reconcile your statements!