| Plan ahead (you probably know this one). Don't get sucked into thinking that "the tickets are cheapest last minute when the airline has empty seats to give away." As a rule, this just isn't how it works (unless you're getting a so-called "weekend excursion" fare). In fact, prices go through the roof because business travelers will pay just about anything to reach their destination last minute. In many cases, your tickets must be purchased 14 days in advance to get the discounted fare, though sometimes the cutoff period is 7 or 21 days. Finally, if you plan on traveling during a peak period, you really want to make sure you book your ticket as early as possible. The problem is not that the cutoff date is earlier - rather, there are only a limited number of discounted tickets per flight, and these tickets are snatched up early during peak periods.
Spend a Saturday night. This is another basic to cheap airfare that most people know. Sometimes you only need to stay 3 days (between your flights to and from your destination) to get the cheap ticket, but, most of the time, a Saturday night stay is a must.
Travel on Tuesday, Wednesday, or Thursday if possible. As a general rule, flights on Tuesday, Wednesday, and Thursday usually have the lowest fares, Monday and Friday are slightly more expensive, and the weekends are the most expensive. It is important to point out, though, that this is not a hard fast rule. For instance, occasionally Saturday flights have discounted fares, and other times the cheap fares are available on any day of the week. The basic logic behind this rule is simple supply and demand. That is, because there isn't the same demand for flights on the "off" days, the airlines typically sell tickets on these flights for less.
Be flexible with your departure times. Just a couple of hours can mean the difference of hundreds of dollars in the price of an airline ticket. Unlike the days of the week, though, pinpointing a time in the day when fares are the cheapest is impossible. Because the demand for various times of the day differs with the route of the flight, day of the week, and other factors, sometimes the cheap fares can be found in the middle of the day, while other times early morning or late evening departure times yield the cheapest tickets. With most travel websites, though, you needn't worry about searching for fares at all times of the day, and here's why: When you perform a search for flights, you have the option of specifying a preferred departure time. Don't. Instead, always make sure you select the the "anytime" option; this way, the site will search all of the fares on that given day to find the cheapest fares available.
Don't limit yourself to one airport - or even one city. For example, if you are going to Los Angeles, LAX is not the only option. Burbank (BUR), Orange County (SNA), and Ontario (ONT) airports are all within driving distance to LA. Many cities have more than one airport, and often you will find considerably different prices to the different airports. So when you do a search at an online travel site, enter the name of the city, not the airport name or code. Then, when the system searches for your lowest fare, it will search through the fares for all of the airports in and around the city. Or, if you live within driving distance of two or more cities, check the fares for both cities. You might be surprised at the deals you can find at alternate airports.
Be patient... Don't think you are going to find the cheapest fare in a few seconds. Give yourself some time to sort through all the options. There are a lot of sites out there, and it really pays to check with each and see what the different sites have to offer. Sometimes an auction site like SkyAuction might have just what you're looking for at half the price of the best fare on Orbitz - and the next time Orbitz might have the best deal and SkyAuction might not have anything close to what you're looking for. So be patient and make sure you've gotten the best deal out there...
...then act fast. When you find the best fare, get it while you can. There are only so many seats on every flight at the discounted rates - and since they're cheap, they obviously sell out quickly (you're not the only one trying to find the best deal). It's a terrible feeling when you see the cheap airfare one day, wait until the next day in hopes of finding a "magic fare" - and then the cheap fare is gone. So be patient while you search through all the options, but don't hesitate when you find the lowest airfare out there