While some people espouse the virtues of “cheap tickets” service, I’ve found that those sites actually add quite a lot of taxes and fees on top of standard airline tickets. What they are useful for is finding out exactly what airlines are offering flights and when.
Look at the list of all flights going to the destination, and pick a time and airline company you want to go with. Then book tickets directly through the airline themselves.
Not only is it cheaper to book directly, but often, it can clue you into deals they may have going for booking in advance, or on a certain day.