1. Sign up for the email list of your favorite airlines. When a fare sale starts, airlines often email their loyal customers. I got a round trip ticket to New York City for less than $160 because Jetblue emailed me when they dropped their fares. Hubby and I paid $39 each way to fly to Portland because we got an email about a fare sale from Southwest. Yes, you will get some annoying emails from signing up, but usually you can tell from the subject line if the email is about a sale or not.
2. Thoroughly search Kayak.com, a site that aggregates travel deals seen on Travelocity, Expedia and others, before you book. I find most of the lowest fares I have booked through Kayak.
3. Fly mid-week for lower fares. Simple but it works.
4. Once you book your flight, register it at Yapta.com. If the price drops, Yapta will email you how to get a refund or credit. Many airlines charge a re-booking fee so the drop has to be significant (generally $75 to $250).
5. Check out TravelZoo.com. I love this site because it sends me travel deals from my local airports. They have many vacation packages and oftentimes the vacation specials page has deals that are eye-popping.
Which airline has the best luggage policy? National Geographic travel writer Chris Elliot says hands down it is Southwest.