1. Pick the right program. You want a relationship with the airline that offers you the most convenient flights. Generally, it’s best to pick the largest carrier at your hometown airport.
2. Put all your eggs in one basket. Diversification is a good investment strategy, but it’s not a sound practice for frequent-flier miles. Because the miles or points you earn in one program usually can’t be exchanged or transferred to others, it often makes sense to participate in just one program.
3. Bag the miles and buy the ticket. Despite your affinity for one airline, if you can find a cheaper flight on another, take it. (Use sites such as Kayak.com and Airfarewatchdog.com to compare prices.) Pay extra only if the miles you earn on the more expensive flight cost less than their redeemable value (a frequent-flier mile is worth, on average, 1.2 cents).
4. Keep your miles alive. Miles typically start to expire if your account has been inactive for 18 to 24 months. You can, however, reset the clock. Aside from booking a flight, the easiest way to ensure that you hold on to your miles is to sign up for an airline credit card that’s tied to your program and use it.
5. Rack up miles on the ground. You should also be aware of each airline’s rewards-program partner companies. The largest programs – those sponsored by Delta, United and American – list thousands of partners on their websites, including retailers and hotel chains. Also take advantage of your program’s “mileage mall,” a network of online retailers that offer reward miles, and use your program-affiliated credit card to make purchases at these stores.
6. Know when to fold ’em. Because airlines have started filling their planes to capacity, the supply of rewards seats is more limited. But it’s still possible to snag a free flight, especially if you book ahead (as many as 330 days prior to departure) or late (two weeks before). Look for midweek flights during off-peak periods, and avoid weekends and holidays.
Michael Stratford is an editorial intern at Kiplinger’s Personal Finance magazine.