What are the expressions of politeness in the cultures you create? Is it people opening doors for others? Tipping a hat? Taking turns? Is it how they address each other? Do they use formal terms such as Mister, Miss, Mrs., Master, Mistress, Captain, Lord, Lady? Do they use words such as Please and Thank you?
And what is the opposite of polite behavior? Swearing? (Which also involves what are the swear words? Are they religious in nature? Reflecting bodily functions?) Are swear words only used in times of great emotion? Or have they become so commonplace, so drained of their power to shock or offend, that every other word a character utters is a swear word? Would a dragon picking his teeth be considered rude, or is it only rude if he doesn't use a toothpick?
What are the taboos? What cannot be named or discussed? Are there food taboos?
Are manners reflective on age or class?
What are the signs of respect in the culture? Do people bow, tug their forelock, or wai (bow over hands pressed palm together)? Is a deep bow more respectful than a mere inclination of the head? Are there gestures associated with the bow? If you have winged beings, are the wings always kept tightly closed against the back? Would open and raised wings signal respect? Or would that (as in many terrestial birds) be a threatening/challenging gesture? If you have a tailed society, is it forbidden to touch another's tail without permission? Is it rude to tap someone with your tail? Are "excuse me" or "pardon me" phrases in common usage? Or are some offenses only cleared by a duel? If different civilizations come into contact, could a gesture considered polite in one culture be considered rude in in the other?
I always enjoyed Georgette Heyer's Regency romances and her depiction of a polite society with the emphasis on manners and rules of civilized behavior. Sharon Lee and Steve Miller's Liaden Universe also has a polite space-faring civilization where rude Terrans misbehave at their risk. CJ Cherryh's Foreigner series is another example of a a mannerly culture. There are many fantasy stories about how wise it is to deal politely with the elves and the Seelie Court.
Sometimes the bad guys in a story are the ones with poor manners. The rude louts who try to destroy everything the hero or heroine holds dear. But then there are also those tales where the villain has perfect manners - so much so that it is scary to watch his or her plans for the world. Sometimes that veneer of civilization is stripped away when the evil plans are overturned, other times the villain remains polite even in defeat. Which do you find more disturbing?
"Where are your manners?" is a question I like to think about when world-building. And I prefer the answer to be "Why, yes, they are in this story."
Do you notice how manners are portrayed in stories? What are some of your favorites?