There's a SECRET POSTURE that supposedly helps you get whatever you want . . . it's called the "KINDLY BRONTOSAURUS."
Approach the person you're asking for a favor . . . like, say, the airline employee at the desk. Give your name, and make your request. If they say no, smile and say, "Well, I'm sure we can find a way to work things out." Stand off to the side in someone's peripheral vision . . . lean forward a little . . . clasp your hands in front of you . . . smile . . . and never stop looking at their face. Eventually they'll help you because you look friendly and respectful . . . and SUPER ANNOYING.