1. Don't use US-based search engines exclusively to book flights
US-based search engines, like all search engines, have blind spots -- they miss budget, foreign, and smaller regional airlines. To get a better picture of who flies where and for what price, be sure to search multiple airfare websites. Two of the best are momondo.com and Skyscanner.com.
2. Don't book your flight too early
The best time to book an international flight is four to six months before you fly, as that’s when the airlines have a better idea of how quickly (or slowly) a flight will start selling out -- and they raise or lower fares accordingly. For domestic tickets, it’s between one to two months.
3. Use our step-by-step guide to hack cheap airfares using foreign websites and currency
Going straight to a foreign airline's website, pretending you’re in that country, and booking with the local currency can sometimes save you hundreds of dollars. And the best part: all of the currency conversions are done by the credit card company. Here's how you do it. (Note: Make sure the foreign airline site you're using accepts US credit cards before you hit "Buy" -- or whatever "Buy" is in that language.)
4. Use hidden-route ticketing when booking your flight
We explain it in more detail here, but essentially, search engines rarely check every combination of connecting flights to a destination, and you can often get there much cheaper by flying through a "hidden," less popular airport. Tripdelta is one site that puts together hidden-route tickets, and on international flights, it can make a huge difference.
5. Fly off-peak hours and days
And that's not just flying between 5-7am or after 8pm, but also on days when people don't traditionally travel. Tuesdays, Wednesdays, and Saturdays are typically the best days for cheaper fares.
6. Buy two one-ways on different airlines
When flying domestically, it can often be cheaper to mix-and-match airlines or buy two one-way flights instead of a single round-trip ticket on the same airline. Look for one-way deals on Airfarewatchdog.com or TheFlightDeal.com and use the American Express travel site to combine one-way flights on airlines.
7. Clear your browser's cookies before buying a flight
According to Min-Jee Hwang of Wiser, a firm that analyzes pricing strategies, airlines use browser cookies to help track your flight search; it's called "dynamic pricing," and it means that prices change based on demand and conditions. While no airline has ever fessed up to doing this, best to play it safe and clear your search history and your cookies before each flight search. Or better still, use an incognito window.
8. Use a credit card that covers checked-bag fees
You can avoid an airline's baggage fees by simply applying for that airline’s branded credit card! Though these cards come with annual fees ranging from $65-$95, if you fly even just a few times a year (or as a large family) on that airline, the money you save more than pays for the card. Plus: bonus miles, priority check-in, security, boarding, and even lounge access! Or, if you want a more general travel card with similar benefits, check out our rundown of the best five here.
9. Fly budget airlines
While we have only a few budget airlines in the United States, the rest of the world is awash in low-cost carriers selling tickets at rock-bottom prices (though be sure to follow their ticketing rules exactly so you don’t get hit with a ton of fees). From WOW, Norwegian, and Ryanair in Europe, to Air Asia, to Tiger Airways in Australia, and GOL and Sky in South America, you have lots of options. In fact, Air Asia once ran a 10 countries in 30 days for just $160 deal.
10. Use these tips to score cheaper tickets on Kayak
From fare forecast and three-day flex search to scoping out the Travel Hacker for popular destinations, here are six ways to turn Kayak into your new flight-booking bestie.
11. Sign up for email alerts and use last-minute deals
If you don’t mind traveling last minute, The Flight Deal, Airfarewatchdog, and TravelPirates.com are three of the best sites to sign up for to score immediate flight deals. Careful though: they may end up in your "Promotions" folder so be sure to check that regularly.
12. Join this all-you-can-fly airline service
Sure, you gotta fly a lot to make it worth it, but if you find yourself traversing coasts (or within your region) multiple times a month, OneGo offers unlimited flights on major airlines for as little as $1,500 per month.
13. Fly into cheaper, alternate US airports
As long as the cost of getting from the airport to where you’re going doesn’t negate the airfare savings, flying into places like Oakland (SF), Ft Lauderdale (Miami), Burbank (LA), and Baltimore (DC) can be a lot cheaper. Here's a good list of alternate airports.
Europe is hip to the off-airport discount game too. If you’re planning to visit multiple countries on your big Euro vacation, chances are one of these 12 airports will be somewhere on your itinerary.
15. Use our step-by-step guide to finding deals on Google Flights
Between the lowest-fare graph, tips on alternate flight dates/airports, and the "I'm Feeling Lucky" function, this guide to Google Flights should tilt things in your favor.