This question is the flip side of Mistook new faculty member to be a student, how big a faux pas is it?
I'm an associate professor, and apparently I look young for my age. When I meet new people at conferences, they often start the conversation with something like "So, are you a grad student or a postdoc?" It doesn't particularly bother me in itself, but when I politely say something like "Actually, I'm faculty", they get embarrassed and it kind of puts a damper on the conversation. I think this sort of thing has probably spoiled a few potential networking opportunities for me.
Are there more tactful ways I can respond to this kind of mistake?
Are there things I could do to "look" more like a professor? I already dress reasonably neatly (e.g. no T-shirts) and faculty in my field don't normally dress up much more than that. Should I carry a briefcase instead of a backpack, or something like that?
(I happen to be cis male, work in mathematics, and live in the US, but it would be good to have more generally applicable answers if possible.)