This is such a great post and a worthy question! I have come from universities that seem to be starkly opposite with regard to their culture. For example, at one all PhDs were called Dr. XX by students, no exceptions. It just seemed to be how it was. Another university was more informal and most Drs. requested informality even if the student seemed uncomfortable with it.

I think the way you dress and look will also influence perceptions- as this seems to be human nature. I think perhaps more meaningful is the way you engage with the classroom, handle conflict or push-back with your students with regard to the points you have raised, and ultimately your confidence in doing so.