When you look for advice on how to dress professionally, you always hear: "Dress appropriately," and "You should feel comfortable with what you wear." OK, the second part is easy: It depends on the season how many pieces you wear, and maybe after Christmas-New-Year-holidays you'll have to adjust your clothes a bit. But "appropriately"?
When you have a job interview, this is a critical question. For people in medicine or law it's easy, you wear a suit as a man and a pantsuit or deux-pièces (skirt suit) as a woman. You want to look like "one of them," you want to look like the other professors. So what do professors in Computational Linguistics look like?
The old men wearing three-piece suits are retiring these days.
When do you see professors wearing formal clothes? Maybe on conferences. Only a few men wear suits regularly, most wear pants and coats, some even wear jeans and pullovers or fleece jackets. Women wear pants and coats, some even wear jeans and fleece jackets (oh, no gender difference? OK, some women also wear skirts or dresses, but I'm not into skirts.) So maybe for very official occasions, I get a bit more formal with pants and a blazer.
But what do you wear on a day-to-day basis? You won't look overdressed and feel comfortable at the same time, so jeans and fleece jacket would be OK? But then you make experiences like I did on my first days in Konstanz, people treat you like another student.
How could I show that I'm a bit more mature than my students? Maybe getting grey hair would help. But that's not the best option, you simply feel old -- not mature or professional -- discovering the first grey hair in the mirror. As a man, I could grow a full beard. But wait, I already had bachelor students with full beard -- so no significant difference again.
I guess I'll have to live with being mistaken for a student from time to time, a deux-pièces simply doesn't go with my EDC -- Kitchensink and Motörizers.