Do your research. It might take a little time, but the payoff is that it could save you hundreds of dollars. Check out farecast.live.com. It's the one and only airfare prediction Web site. You enter your dates and destination and it will provide you not only with the best time to purchase your tickets, but also with a comparison of prices from the different airlines and travel sites.
Look to a professional. A travel agent can sometimes match or find a better deal than Internet searches. I think this is a great option that many of us seem to bypass or ignore.
Keep your travel options open. Travel on off-peak days like Tuesday and Wednesday and avoid major holiday travel days like the day before Thanksgiving or Christmas.
Consider flying in to smaller airports. Think Burbank, instead of LAX or LaGuardia, instead of JFK. This will give you additional scheduling and fare options.
Take "additional charges" into account. This can send your bargain fare right out the window. With airlines now charging for snacks, drinks, checked bags, and even pillows, it pays to remember to take these charges into account when you are searching for your flight.
If you see a good fare, grab it. That mistake could cost you hundreds. Don't wait another day before booking your flight. Once you find a bargain, make sure to check your flight regularly to ensure that nothing has changed. Airlines are known to make changes often and it pays to be prepared.