Check the prices for the air fares you are interested in at the airline's website as well as on travel consolidator websites such as Orbitz, Travelocity and Cheaptickets. Take an average of the fare cost and use this as a basis for your bids at the bidding website.
Check the fares for nearby airports. If you are traveling to a metro area with more than one airport such as Los Angeles, New York City, Chicago and San Francisco, check the other airport fares. Use this to make bids for your travel.
Use a set of days for travel versus just one, if you have the flexibility. Having a window of days lets you find cheaper fares when bidding. Tuesday through Thursday are traditionally the cheaper days of the week to get cheaper fares.
Log into the bidding website and enter your dates, airports and the first bid. As a general rule of thumb, make your first bid 25 percent less than the cheapest fare you found during your research.
Make an additional bid if you are denied. Try using a 15 percent below advertised price bid to secure the one way fare. Priceline asks you enter your credit or debit card information as you make your bids. If the bid is approved, your card is automatically charged and the ticket purchased. Priceline limits bids to two per trip within a 24 hour period on certain fares. Read the bidding screen to see if your fare qualifies for the restricted bidding.
Print a copy of your itinerary once the bid is approved, the fare purchased and the confirmation screen is up.