Update: To always have the latest airfare strategies at your fingertips, bookmark this guide to cheap flights: Tips to Find Cheap Airfare.

Over the last year or two I’ve done my fair share of flying and have refined my methodology of making sure that I always get the cheapest airfare available. I wish I could tell you “use this one service,” but in reality it doesn’t work that way. Since there are so many variables at play, you have to run searches at a number of sites. So how do you get the best airfare?

There are basically three types of airfare websites: 1. Aggregators (ex: Kayak) that check airfares for many different airlines. They do not charge a fee but instead rely on affiliate hotel deals and on-site advertising like Adsense to make their money. These are historically the best bets. 2. Traditional booking engines (ex: Orbitz) that check multiple websites and take a small fee ~$6 in addition to the price of the flight. They process the sale on behalf of the airline and keep the fee. 3. Airline’s own websites (ex: JetBlue). If you find a flight on booking engines, check the airline’s own site so see if you can get it for the same price minus the booking fee. The important subset of this are airlines who do not play nice and do not offer their fares up to aggregators (ex: Southwest). You have to check their sites individually.

In my experience there is no ONE website that you can use to get the lowest airfare every single time. It fluctuates quite a bit because there a LOT of variables involved. Don’t ask me why – it’s just how it is.

My recommendation to get lowest airfare:

You can also dig deeper using the quick list on the right. Try different days if you can (one day before/after), nearby airports (usually there’s a checkbox for that), and also check out building the flight with one-ways instead of round trip. This works especially if you have a 3-way flight or find that Southwest has a great 1-way price, but not roundtrip – then you can just use the other engines to get a cheap 1-way flight back.

If you feel really ambitious, check the airline’s own websites – list on the right (sometimes they’ll have unpublished deals).

When you find the cheapest flight that suits your needs, go ahead and book it. One of the things you’ll eventually run into is “oops, that $280 flight is now $320? messages. It will annoy the hell out of you. But that’s just how it is. You might want to check the other aggregators – sometimes you can catch what you just missed on and one and find it on the other.

Since travel is a big industry, there are a lot of shady websites/clubs/etc. that try to get your email address or try to get you subscribed to some service. I’ve never found those very useful for actually finding cheap flighs. The only exception is TravelZoo. I’ve signed up for their weekly Top 20 Travel deals email and I can say I’ve seen some impressive deals there.

Note: The above is mostly for US flights. If you’re looking for International, check out vayama.com, skyscanner.net, momondo.com, and trabber.com (non US). I haven’t tried them myself but I hear they’re good.

Feel free to share your flight booking strategies in the comments or give some travel tips of your own.