Here's some tips for the non travellers -
If you want cheap flights, shop around travel agency chains and get quotes for more than 1 airline.
Not all travel agents have access to the same fares, some have "private fares" that have been negotiated with the airline specifically for their company only.
Also, if flying overseas, the direct flights are the most expensive, so look at flights/airlines that stop at some point of the journey.
And some airlines now charge additional taxes for credit card payment, so pay cash if you can.
And of course, the earlier you book, the better chance you have of scoring cheaper flights, however the fare rules are more restrictive on the cheap fares, so you will have to pay if you need to make changes once the ticket is issued.