Fly on multiple airlines. Looking for flights on single airlines may be the easiest, but you may have better results if you look into flying on multiple airlines. Try taking one airline to your destination, and a separate one from. Or, include a layover with another airline mid-flight. Breaking up your trip and splitting it between carriers is likely to save you money, which is worth the extra time and hassle it will cost you.
Fly out at the right time. As with most of these search related parameters, turns out what we want the least is what makes the cheapest flight. The earlier your leave on a flight, the cheaper it will be. Red eye flights (in the middle of the night) are by far the cheapest, followed directly by early morning flights. Although you might luck out on a rare evening steal, typically the later in the day you depart, the more expensive your ticket will be.
Vacations aren’t cheap so you might want to find everything
In Google Chrome or Safari, incognito is enabled by hitting Command (or “Control” if using PC), Shift, “N”. For Mozilla Firefox or Internet Explorer, hit Command (or “Control” if using a PC), Shift, “P”. This will open a new browser window where your information is not tracked, thus not inflating prices as you search. Note: if you're using an older version of OS X, open Safari then click “Safari” in the menu bar, and select “Private Browsing”.