Booking flights online

momondo, skyscanner and google flights are good comparison sights

Or they'll lead you down the merry path with a cheap fare, then bump it up when you get to pay.

Not always the case. Last year a group of us where looking to go away and on the Ryanaiar website it had 3 seats left at this price so I booked, when the another person went to check later the new batch where cheaper than what I booked at.

A few minutes after I'd booked. I'd got the last seat when I booked the other 2 had gone.

It also depends on how many seats you want - you might get the last at a particular fare but if you wanted 2, those seats might have different prices. This usually applies to Legacy airlines and not LCC or charter flights.

don't book at the end of a month as Ryanair know you just got paid.

airhint.com will give advice and regular email updates as to when to buy a particular flight.

Booking 8/10 weeks out for a long haul can be cheaper.As one poster said be happy with the price you pay at.Some airlines trend prices over a 2 week period-up/down by a few euro then lob on e50,keep price up for another 2 weeks which seems the normal cycle then shoot up as your travel date approaches- 4/5 weeks out.I am monitoring flights in January(end of).One airline has varied by e40 in the 6 weeks,the others by e150-350.This week all with e100 of each other.To me that means no demand yet.Pay the price you're happy with and leave sites alone.Skyscanner the best.Googleflights the worst.Others 50/50 but they forget the extras which are included by other sites.Like baggage is 23kg not 25 or 30kg.Seat fee is excluded and charge more than the airline or even when free with the airline direct