1. Be flexible.
Opt for mid-week, mid-day flights when possible; skip large hubs in favor of smaller, alternate airports that charge less in taxes and attract low-cost carriers; and search up to three days before and after your ideal departure and return dates.
2. Always peek at roundtrip airfares.
Even if you're booking a one-way ticket, the roundtrip may cost less. (Just make sure you're flying on the outbound portion of the ticket. If you don't show up for that, the return will automatically be cancelled.)
3. Set up automatic fare alerts.
Airfares change periodically during the day. You don't have to keep checking back-let the search-engines do the tracking work for you and arrange to have e-mails sent to you when fares fall into your desired range. Start with Airfare Watchdog. (http://www.airfarewatchdog.com/) It spots bargains from Southwest Airlines––not all aggregator sites do.
4. Hit hotspot destinations off-season.
Summer is peak season just about everywhere but you can get deals in hot (temperature-wise) locales: Various Caribbean islands, Florida and Mexico offer rock-bottom prices through October if you're willing to risk a hurricane. And top resorts in desert destinations like Palm Springs and Scottsdale are a steal right now. The rest of the year, try to hit Disney between Thanksgiving and Christmas, Europe in September and October, and ski resorts in late November and early December. Not only are flights cheaper, hotels are emptier and lines shorter.
5. Book early.
While you can find deals up until the last minute, it's hard to predict which flights will go on sale. If you have a specific locale in mind, always try to buy your ticket at least 21 days in advance. The longer you wait, the harder it is to get a steal because as seats fill up prices climb. That's especially true now, as airlines prepare to shrink the number of flights and routes they fly. Tip: If you're not picky about the destination, keep your eyes peeled in August for fare sales on early fall travel.
6. Search smart.
The best way to comparison shop is to use airfare aggregator websites. Unlike major booking sites Expedia and Travelocity, which charge processing fees, these turbocharged search-engines hunt scads of agencies, airline and travel sites to unearth the best bargains-at no cost to you. Once you pick a flight, you're directed to a vendor site (or a booking site, depending on which airfare you choose) where you can buy the ticket. Casting a wide net will help ensure you get the lowest airfare possible, so use a variety of engines. Here are four of our favorites:
Sidestep.com (this was acquired by Kayak, but maintains its unique features)