Apart from saving money on air travel another very important matter is not to waste money.
The background to this, is that there is no website or app or anything else (apart from, of course, a proper travel agent) who, when selecting flights for a travel event, considers inter alia, the most favorable fare rule conditions when selecting your flights. You may have read, in a previous post, how a United Airlines fare offered more favorable fare conditions than (in that instance) did British Airways.
What else can one do to prevent wasting money?
Do not book anything unless you are 110% sure and if you are unsure, then book something flexible or at least, with some flexibility. Business class, though expensive, is there for a reason. Actually, short haul and some medium haul "Business Class" does not really exists. Originally, the designation came about when airlines decided that they would take those people that had booked a full flexible ticket, put them up front, give them a bit more space and give that bit of the cabin a fancy name. Long(er) haul is different, you do get priority this and that, a nice seat or bed, better food and so on. That said, you are paying a huge premium. My own opinion is that the new style "Premium Economy" cabins offer better value for money with just enough extra comfort - but as I say, that's a personal opinion.
Flexible tickets are available on some airlines and routes without having to go to the cabin at the pointed end. You don't have to travel business class, in order to get something (relatively) flexible.
Let's look at Frankfurt (FRA) to Madrid (MAD). We are travelling on the 15th September and returning on the 18th September. I can travel with Lufthansa or Iberia. The meeting I need to attend, however, may be cancelled; but I do need to be there. The best price offered by Iberia is £221.00 and by Lufthansa £300.50 - but if I have to cancel, with both these fares, I don't get much, if anything, back. Business Class, with both airlines will leave me little or no change from £1,000. Lufthansa offer a flexible fare, though, of £409.50 and at this fare, if I cancel I will lose 70 Euros. BUT I can buy a fare on Iberia for £390.00 which I can cancel for only 60 Euros - and there is another big benefit with the Iberia fare. That is, the position of the fare in the food chain.
If I have to change my flights on either airline, changes are free, though I have to pay any fare uplift, if only more expensive seats are available. The Lufthansa fare, is actually much further down the fare food chain than the Iberia fare (Lufthansa is V and Iberia K). K is three notches down from full fare, V is 6 so if a change is required I would stand a better chance of getting a free change on Iberia than I would on Lufthansa.
(Note: Both/ All airlines mentioned above are well respected. The fare statements above are a matter of fact, not sentiment!)
If you do not travel then always claim back unused taxes. Even on non-refundable fares, unused taxes are generally refundable and these should be claimed. Many online websites make a song-and-dance about this but the process itself, for an agent, takes very little time. That said, there is no law that says any airline must refund unused taxes but most airlines will do the honorable thing.... IF you ask them.
Your agent will tell you which taxes are refundable and which are not (YQ isn't, for example) but those taxes payable by any airline, only when you actually fly, usually are. On an economy fare to New York from London, for example, you could get back £165.00 - and if "non refundable business" £240 (not much on a fare outlay of £2,500-odd, granted, but money is money). Note that you may have to pay an administration fee and have to wait a while. Some agents will not charge an administration fee if you are a regular client, of course. (I don't charge for refunds with regular clients). Low cost carriers are not quite so forthcoming on this front, Easyjet, for example do refund but many others do not.
Given that it has been estimated that airlines (ex UK) trouser a tidy £350 million plus in unclaimed Air Passenger Duty and other taxes, you may as well get your bit back!
Booking well in advance is not very helpful advice, frankly. There is no point booking anything well in advance unless it is, say, to visit the family at Christmas tide or some other public holiday, when the world and his wife are travelling. My own view is that one has to be pragmatic, if you cannot book, then you cannot book and like in the example given passim, if it is something you do need to get booked but are a little unsure, book the most appropriate fare for your circumstances rather than what is simply "the cheapest".
.... to be continued!