My general strategy for airfare is patience, but I used a number of tools.
First, I set a deadline that I will book by (e.g. for TOAL, I will likely set April/May deadline).
Second, I set a price I want to pay (e.g. for TOAL combined airfare per person of under $200 - don't laugh, for June trip to WDW, paid under $650 for 4 of us, after taxes and fees - its patience)
Third, I use some fare alert services (usually I use the Orbitz deal detector which lets you set dates and what you want to pay e.g. April 10 there, April 15 back and $100. It will send you a weekly update on fares and an e-mail or txt when it finds your fare. I usually use e-mail, so the fare may be gone by the time I get e-mail. When I get the alert....see Fourth below. One note, Orbitz's tool will only do round trip so I will set it for two week intervals and search for one that will do one ways)
Fourth, when an alert comes in and also periodically (weekly) I will use an all in one service to search multiple airlines for fares. Two examples are
Sidestep and
Kayak. Discount airlines such as Spirit, Southwest, etc. will NOT appear on these search engines so you need to search their sites separately.
Last, when you see the fare that is the "best" you think will come along, book it.
Now there are a few counterintuitive things you need to understand about airlines and airfare:
1) Airfare is cheapest when the plane is empty. Airlines need to have a certain number of passengers to make a flight profitable, so they give their cheapest rates up front to fill the plane to profit level and raise price on remaining seats to maximize profit.
2) Once a plane is full (95%) the airline will bring a new plane on line with similar flight times (e.g. when 9 a.m. fills, they will bring a 9:30 on line). When this happens, airfare drops back to lowest. This means that if airfare goes very high and you are 6+ months from when you need to fly, patience can be very rewarding (unless some intervening event e.g. gas prices, changes fee structure).
3) Periodic airline fare sales throw 1 and 2 out the window. Tom's Law on airfare sales: the flight you want will be the only one NOT on sale. If you are flexible, the sales can save you some bucks.
4) Not all airlines are the same when it comes to seat assignment, etc. Some airlines will not give you seat assignments for discount fares until you arrive at the terminal. This means you need to do on-line check in or get there early to get seats. Coming back from WDW I had to go to gate to get seats and they had 4 separate seats for us (meaning DS8 and DS10 were sitting alone with strangers - fortunately the very kind and highly complimented gate agent rearranged so DW and DSs were together and I had to sacrifice in exit row....). KNOW THE AIRLINE RULES when booking.
5) Non-stop can be as cheap or cheaper than connecting flights.
6) Expedia and Travelocity are discounters and they contract with airlines to purchase tickets at a fixed rate (e.g. they contract for $75 per seat). As the airlines airfare increases, so do the discounters (e.g. now they make more money). Sometimes they will have the cheapest rate available (or only seats on a flight) and other times the airline direct is cheaper. SHOP BOTH.
Hope this helps some of you.
Good Luck 
