Many websites offer airfare rate comparisons. Popular ones include Priceline.com, Expedia.com, Kayak.com, Orbitz.com, Travelocity.com, Airfares.com, TravelZoo.com and Bookingbuddy.com. Choose at least three to compare fares. Go to each website and enter your flight information: destination, date of departure and arrival and number of passengers. Enter the same criteria on each website to get an accurate comparison.
Airlines often offer web-only discounts and specials that might be lower than what you will find at the rate-comparison sites. Check the airlines' websites for rates. Sign up for frequent flier programs for more discounts. Check discount carriers such as JetBlue and Southwest. Some airfare comparison websites do not include those in their searches.
Changing the departure date by just one day or the time by a few hours can save you money. The same is true for airports, so check all airports surrounding your destination and arrival cities. The best time to buy your ticket is Tuesday or Wednesday, since that's when most airlines announce fare sales.
If your trip is a few months away, you should sign up to receive fare alerts by email. Many airlines offer this free service, so sign up for all airlines that fly to your targeted destination. Some websites, including Yapta.com, will track fares for various airlines and send you an email when the price drops to your targeted price.