Tip no. 1
To get the best deal on any product you have to buy and compare prices. The same goes for plane tickets. If you want cheap flights, compare the price between several different airlines. This task could easily be done by using some of the famous travel websites, such as Orbitz, Travelocity, Expedia, Cheap Tickets, CheapAir.com, Booking Buddy.
Sometimes you have to search different travel websites to get the best result. But there are websites that search 100 plus travel sites at once and find the cheapest rates. kayak.com is one of them. My favorite is itasoftware.com
Tip no. 2
To get a plane ticket at the cheapest price, you will need to know the historical cost of your itinerary. Once you find your ticket for a ticket at or below that price, then you know it's a good deal. FareCompare.com will do it for you. At FareCompare.com you will find cheap airline tickets, discount on first class airline tickets, the easiest tools to plan your air travel. FareCompare.com keeps track of airfare so you will be the first in line to get the best deal on a cheap flight. On their results page, under Quick Links, you can view historical deals and subscribe to Alert Me on Price Drops. FareCompare.com will send you an email when the trip drops.
Tip no. 3
You can get a cheap plane ticket even cheaper with an airline coupon, others may call it a voucher. Northwest Airlines is expanding the voucher zone to the general public. I got them in a Val Pak coupon. Continental Airlines issues a dollar voucher based on the return airline ticket. They have recently partnered with Chase Bank to lead the promotion. United Airlines compensates customers with $ 50, $ 75 and $ 100 vouchers.
People post these vouchers on eBay, sell.com, craigslist in exchange for good or money. Some of them have no monetary value (just like a grocery coupon), you pay for their time to collect and send vouchers.