"Or ... How about a student that keeps asking you to school her on something when you are trying to sew. There should be a set of rules on the walls."
I work with a pretty diverse group of folks (by which I mean that we are from a variety of countries and cultures) and in meetings for projects we DO put the rules up on the wall! Why not for quilting classes? The rules arepretty basic 'no sidebar conversations' 'no off topic discussions' 'never provide negative comments', pretty much the kindergarten stuff.
But itmakes sure that we are all coming from the same point of understanding. Something just as basic would work for class.