On a short flight there's not much in the way of interactions so I just ask for my beverage of choice and leave it at that.
For long haul, I definitely do my best to be courteous regardless of whom I am talking to. Sometimes it does encourage more positive attitudes from the people you talk to, but if it doesn't I don't spend too much time thinking about it. If it was particularly bad I could see myself complain after the flight and maybe get some compensation out of it, not that I think I'm entitled to it, airlines just seem to want to deal with such complaints with free miles.