pay fees when you cash in your frequent flyer miles. "There's no such thing as an absolutely free ticket anymore," Brancatelli says. Airlines require you to pay taxes for your flight, which could range from $5 to $50 domestically and up to $600 internationally, and many also impose a fuel surcharge. On a British Airways flight from Washington to London, Brancatelli says the fuel surcharge alone could be from $300 to $400. Those kinds of fees can't be avoided, but if you plan your trip far in advance, you can avoid late-booking fees. A number of airlines charge a fee for "close purchases," which is typically within 21 days of the flight, Brancatelli says. Booking your trip a month in advance will help you avoid that extra fee. It's best to redeem your miles through the airline's mileage program website rather than over the phone, because most airlines will charge a fee if an operator assists you. For example, AirTran charges $15 for booking a flight through its call center. "Like with any ticket you now buy, there is an additional fee for the call center," Brancatelli says. The tradeoff? The call center might be able to find you a seat that's not available online. "No airline website is totally comprehensive," says Brancatelli. For more complicated purchases, such as trips with multiple stops, the call center may be worth the fee. Save your frequent flyer miles for high-value, international, first-class travel. "Personally, I wouldn't spend 25,000 miles on a domestic