We always travel from our local airport which severely limits choices but makes for a much more pleasant journey with daytime flights etc. I've found that by monitoring the operators website, I can pick the best prices at certain times of year. The differences are amazing. My latest holiday has varied from £820 per person to £1180 for exactly the same holiday, depending on what time of year you book. I used to wait until four to six weeks before departure date for the cheapest prices but have found that just after Christmas can be as cheap, if not cheaper! We have booked one of the top hotels, half board, cheaper than it would have cost to go self catering in an apartment. Our price includes the transfers too.
If you have time on your hands (which I do) just keep looking and make notes.
