This isn't going to be a very long post because my strategy for airline tickets is very simple. I sign up for "Net SAAver Alerts" with american airlines and check every single day. This is a feature that american airlines offers "aadvantage" members that displays the fare sales of all your selected cities on the home page. "Aadvantage" is their frequent-flier program and there are no associated charges. I live in Chicago but my boyfriend and I are both from Austin, so we fly there at least twice a year for thanksgiving and christmas. Because I know that I have a constant need for tickets to Austin, I add it to my fare sale alerts list and then go to american's homepage every day. That way as soon as a sale that includes thanksgiving or christmas dates comes up (and believe me they do not like to put these heavy-travel times on sale so the tickets go fast) I can snatch them up right away. I bought our christmas tickets this weekend and our thanksgiving ones about a month and a half ago. I also use this feature for vacations- I have many destinations that I would like to travel to on my list and when a fare sale arises for one I will know about it and be able to plan my trip around the dates that are on sale. This is how we flew to new york for $98 each round trip.
Yes this method isn't very sexy or top-secret, but I like it because I hate going so many different sites looking for plane tickets (expedia, hotwire, travelociy, etc), not knowing which one is giving me the best deals. This way I only have to go to one website, and I know that I will be flying on an airline that is trustworthy. American also has a policy that the lowest ticket prices for their flights will always be displayed on their own site, which I have found to be true. By spending a few minutes a day and planning ahead I save myself money and the stress of spending hours searching for flights before each vacation.