Book in Advance and Be Flexible on Flight Times

Waiting until the last minute to purchase is like playing roulette—sometimes you'll get lucky, but more often than not, you won't. While we have all heard of people obtaining a real last minute bargain the general rule with airline tickets is the earlier you book the larger the saving. Most airline sources agree that anything outside 21 days before takeoff is considered an advance-purchase ticket. Airlines are different, but generally, once you hit 15 days before the flight, the price begins to go up, and then it goes up again at the seven-day mark. So if you want a retail ticket, buy it at least 21 days out for the best price.

Flights on popular routes fill up quickly. Also, as the airlines struggle to cover increasing fuel costs, this expense is passed along to passengers in the form of fuel surcharges, which can add up to $80 or more each way. If you book early, you may be able to lock in a fare with a lower surcharge. Travel agents advise booking as soon as you know your plans, especially for holiday travel, travel over school breaks and travel to destinations during peak season.

If your trip to Chicago can wait until the middle of the week or your mother doesn’t mind you arriving on Thanksgiving Day rather than the day before, consider changing your strategy.

When searching for fares, try looking for flights on different dates; sometimes flying even a day earlier or later than your original travel dates can save you a bundle.

Timing when you fly is just as important as when you buy. Though airfares can be fickle and inconsistent, cheaper flights are typically available on weekdays, as opposed to weekends, and during non-rush hours. If you can’t avoid major holidays, like Christmas, New Year’s, Thanksgiving, national long-weekend holidays and spring break periods in March, a good rule of thumb is to try to travel when everyone else doesn’t want to. Think Christmas Eve or day, Thanksgiving Day or a week ahead of time. Flying on a holiday has its benefits—the airports and planes are usually less crowded, and the “we’re all in this together” atmosphere can lend to an easy-going travel experience.

You can find cheaper flights by flying to a destination during a less busy time of the year and less busy times of the day. Popular destinations such as Europe and Australia have distinct high seasons when more travelers visit, and, during these popular times, prices for flights go up to meet the demand. If you can travel to a place when it's less popular to visit—October through March in Europe, for example—you may be able save 50% or more.

Which days of the week you fly and when you choose to travel during the day can also make a difference. Peak hours when flights are at their fullest are 8 to 11 am and 4 to 7 pm. Good deals can be found on 'red-eye' overnight flights which people like to avoid or midday flights can also cost less..

Midweek flights Tuesday through Thursday tend to be cheaper. If you must travel on the weekends, Saturdays are generally the most affordable option.

Although some airlines have done away with Saturday-night stay requirements, including a Saturday night in your itinerary may still lead to the lowest fares. The fine print of most sales will also usually include minimum and maximum stay requirements.

To secure the lowest fares on any round-trip route, space must be available on both the departure and return flights. If it isn't available in both directions, one leg of the trip can increase the price of the entire itinerary. It's worth experimenting with travel dates and even times until you find the lowest fare.

The more flexible you are about when you fly, the better your chances of finding a cheap ticket.