General Anytime Airfare Buying Tips:

• Shop on Tuesday mornings. Fare sales are often launched Monday nights, so other airlines have matched their prices by Tuesday morning.
• Search how full your flight is. You can tell if your flight is full or empty by starting to buy tickets online and “choosing your seat.” That will show you how many seats are taken already. Remember it’s a gamble. When in doubt, booking earlier is safer. If you wait, fares could go up or down, and usually fares go up by more than they go. Only bide your time if your flight isn’t too full and you know the price is a lot higher than it should be.
• If you decide to wait in the hopes of a price drop, sign up for fare alerts offered by practically every travel site, from American Airlines to Travelzoo. Yapta.com, another price-tracking service, alerts travelers when the price of their plane tickets drop after purchase, allowing travelers to request an airline voucher for the price difference.
• Buying two one-way fares on separate airlines can be cheaper than the best round-trip price. Kayak.com calls such tickets “hacker fares.” A recent search on the site for a flight from Boston to San Juan, P.R., turned up a fare of $313 on Delta to San Juan, returning on US Airways, compared with $349 round trip on US Airways alone. Kayak’s “Hacker” tool can help you find two separate one-way flights to make a round trip that saves more money. Kayak also offers a fare chart so you can see trends in the ticket prices, and Bing created a price predictor tool to help you guess if fares are going up or down.
• Follow airlines. Some airlines promote one-hour sales on Facebook or Twitter only, so follow an airline for the best deals.
• Consider a destination serviced by low-cost carriers. Carriers like Air Tran, Southwest and Frontier drive down all airfares along their routes. So it might make sense sometimes to drive longer to go to a bigger airport with low-cost carriers, since even major carriers’ flights will likely be cheaper.
• use a flight booking aggregator site like Booking Buddy. Booking Buddy pulls together 29 aggregators, like Kayak, on one page. You must choose which aggregator you want to use for your travel search and then return to Booking Buddy to search another aggregator, but it’s very nice to have all of ’em in one place. A few of the Booking Buddy choices:
  •     Travelocity
  •     Kayak.com
  •     United.com
  •     Priceline.com
  •     Orbitz
• Beyond historical trends, there are also some useful online tools that can help you evaluate fares. For example, Bing.com offers a Price Predictor that uses algorithms to determine how likely a fare is to rise or fall during the next seven days. It applies to flights from more than 250 cities in the United States and to top domestic destinations and major hubs in Europe.
• For the cheapest dates to fly, go to Itasoftware.com, which allows you to scan an entire month’s worth of fares. To buy, you must go to the airline’s Web site or online agencies like Travelocity.

Tips for Flying Around a Holiday:

• Commonly known, Thanksgiving is the absolute hardest to buy tickets for, because everyone is trying to fly out and return on the same days (Wednesday to Sunday). Christmas is more flexible because people choose different days off. Notice when holidays fall midweek. For example, if July 4th falls on Wednesday (like this year) some people take time off before, some after. This allows you more flexibility in buying tickets.
• Buy at least three months out. Aim to buy Thanksgiving tickets the Tuesday after Labor Day; don’t book too early because rates will usually come down at least a little after the summer, when rates are high because gas is expensive.
• If you can, avoid Sunday flights and traditional travel days. That could mean leaving before and coming back later than most people, or flying on the holiday itself. You can often save 50% on a ticket by flying Christmas Eve or day. Travelers have been known to save over $300 per ticket around Thanksgiving for a family of four by flying out the Saturday before Thanksgiving and coming back the Saturday after. Not everyone can swing that with their work schedules, so standard advice is to leave Thanksgiving day and return on Saturday for cheaper fares.