Flight attendants are usually pretty smiley, nice, and overall helpful, as long as you don't do something to leave them with a sour taste in their mouths. The same goes for anyone working in customer service, or hosting, of any kind. I can tell you that back when I was a waitress, a big grin and a kind word went a long way. If an entitled Karen showed up, I would not go out of my way to do a good job, but rather, I might have opted to be petty, and he or she would have been none the wiser. One…