I don't usually pay too much attention on what I wear. As long as it's decent and comfortable I'm fine with it. Luckily I have a job where there isn't much of a dress code either so I usually don't have to worry about such things there either.
As I'm progressing on my professional career there comes situations where I do need to pay more attention to my apparel. Sometimes I need to attend important customer meetings as an expert. And it really doesn't suit the situation to dress too casually.
The problem with that is, that those are quite nervous situations. You should be at your best. And being uncomfortable in your clothes really doesn't help that. And usually I have found those more formal outfits being just like that, something I don't feel being myself wearing them.
But I have realized that it's no different than propping up for a larp. You wear an outfit suitable for a perfect character in that situation. You become the person others are expecting to meet. Using that mentality has made me even more confident being in those situations. Helped me get over the impostor feeling trying to rely solely on my knowledge, taking the focus away from it. Fooling myself to be the expert I hopefully am. And hopefully also giving a good impression as a whole.