When I was a young lawyer many years go, I had my first DUI trial. In fact, it was only the second trial of my career. I was completely focused on preparing questions for cross-examination, anticipating evidentiary objections, rehearsing my opening statement in front of the mirror, and outlining my closing argument. The last thing that crossed my mind was what my client would wear to court. Much to my chagrin, Mr. Defendant showed up to his jury trial not only wearing a hat in court, but a hat promoting a well-known beer from St. Louis. This defendant was convicted, and that day I learned that "fashion advisor" is an integral part of any courtroom lawyer's job.
Appearance isn't everything, but it does play a big role in how people perceive you. This is true at work, the gym, the grocery store and at a bar, so it should come as no surprise that a judge or jury will not only judge you based on the facts of the case, but also on how you look in the courtroom.