Etiquette is about manners and protocol. You can get by with common sense and courtesy. But some etiquette rules really do have to be learned, especially when dealing with cultures other than your own. It could be an interesting career choice.
If you wrote a character who is an etiquette consultant how would she look, speak and what would her (or his) body language be like? Could there be an etiquette consultant who dresses sloppy, maybe even a little on the rough and dirty side? What story would you write behind that character?