My mother cared an inordinate amount about how I dressed. I always reflected badly upon her. I accepted a long time ago that I am the world's most boring dresser. Usually appropriate, if unimaginative for work, but the rest of the time it is a toss up. I rarely choose to do anything where jeans and a shirt are not perfectly acceptable attire. The therapist is actually one of the last things I would actively dress up for, I would not want the woman to think I cared what she thought of my appearance.
And of course, the ability to freely move to get away quickly should it become necessary.