I would say that the most important thing to do is spend twelve months or so watching the airlines that you might like to fly like a hawk.

You will then know how they price their first class tickets on-peak, off-peak and in sales. You will also see when and on which routes sales tend to happen. Set up an Excel model to analyse the trends and patterns.

It might not help for this year's holiday, but for the next and subsequent years it will save you a lot of money, so much so that it is probably worth the effort.