The best way to find low airfares is to shop around. Before you do, however, determine your budget and availability for travel. Both factors will help define a “good deal. There are several online travel sites that give great access to bargain flights, especially for last minute planning. But don't forget that travel agents in larger cities can often track down even better rates. Decide what you're willing to pay, and when you find a fare that works, grab it. It might not be there a few hours later.