Unlike American hotel receptions you can’t really give a backhander to a flight attendant, although it would be interesting to give it a go, you could of course, get married and hope they upgrade you when you arrive at the check-in desk or try and dress up smartly and travel alone (all of which may help your upgrade attempts).
Recently a British Airways’ flight attendant on a trip from London Heathrow to San Jose, decided to spill the beans to Cosmopolitan writer Catriona Harvey-Jenner.
The only way you can increase your chances are by not booking / pre-selecting a seat at all. If you book a seat the airline has your seat and you’re placed in that seat, it’s a pain to move you from that seat on the system.
But, if you don’t have a seat pre-booked then you’re supposed to just sit where ever there is a space or in most cases where they assign you a seat.
Once you’re sat in that seat then see if you can have a quiet word with an attendant and see if there are any more suitable locations on the plane.
You could attempt an arm touch that Restaurant staff use to increase their tips on the attendant in the hope they like you more but again this could go horribly wrong!