Know your allies. “Look into partner airlines and alliances.” If you have miles with American Airlines, for instance, you can usually put them toward flights on British Airways, Iberia, or another sister airline. Check Airlinetechnology.net to research airline partnerships.
Be an early bird. “Frequent-flier tickets can go on sale 11 months in advance,” so book early. Make reservations over the phone with an agent; online searches “won’t pull up award flights on a partner airline.”
Streamline. “You’ll earn award travel faster if you do most of your flying with one airline or within one alliance group.” Don’t open accounts with multiple airlines in the same alliance.
When all else fails, upgrade. If you can’t book a flight with miles, “don’t sit back and let them expire.” Upgrading that coach ticket you bought to a first-class one is “one of the easiest ways to use miles.”
Source: Real Simple