Historically a way of saving on airfare is to book last minute. The internet changed all this and real “last minute” offers seem to be gone as unsold supply can usually still be bundled and sold online.
Nevertheless there are still ways to save on airfare.
Use online tools
My favorite to find a cheap airfare is kayak.com. Kayak is consolidating rates from many different sources (individual airlines as well as other travel websites). Kayak offers other useful features like “price trend”, “price alerts” and “flexible date” search.
Another interesting site is fly.com. They offer a fare calendar that shows you the cheapest flights from the airport of your choice.
Even after you already purchased your ticket could still save some money at least on your next trip. Most U. S. airlines offer refunds if your price becomes available for less after you book it. Yapta.com does the checking for you!
I usually stay away from CheapOAir.com as they seem to add their own hidden “booking fees”.
Plan in advance
The days of last minute being the best way to score a cheap trip seem to be gone. It usually pays off to plan in advance and buy your tickets early (at least 6 weeks in advance).
The cheapest days to fly are usually during the week (Tuesday and Wednesday). For popular destination (e. g. Europe) you should also consider travelling in the shoulder season. Besides getting a better price you might even enjoy your trip more if it’s slightly less crowded.
Airlines continue to come up with new fees (e. g. checked baggage). Travelling light might save you $50 or more by not having to pay for checked baggage each way. Check out airline fees at http://www.kayak.com/airline-fees.
Always look into Round Trip Tickets
Even if you only need a one way flight you should always check for round trip tickets. Most of the time one way tickets are the same price or even more expensive than a roundtrip ticket. Even if you buy a roundtrip ticket you can just skip the return flight.
Buy Hotel and Airfare packages
Nowadays leftover inventory is very often bundled up as hotel and air package at a great price. This might work out in your favor to get a better deal.
Get back to the same Airport
Having the same airport for your return fight that was your original departure airport usually yields the best price.