Though it should go without saying, dressing in a matter befitting court proceedings is a necessity. When in doubt it’s best to fall somewhere in the middle of the apparel spectrum: Don’t dress in a slovenly manner (no ripped jeans or T-shirts advertising your neighborhood bar), but you also can’t go too far towards the opposite end – if you show up wearing a black tuxedo and top hat or a sequined cocktail dress there’s an excellent chance the judge may construe this as making a mockery of their court and charge you with contempt.
So, again, middle is where you want to be – for men a suit and tie is not even necessary; tasteful slacks with a neatly pressed polo pullover should be sufficient. For women, a conservative dress or slacks and blouse should be good. There may be occasions when an attorney will suggest particular attire for the courtroom; it might be best for you to follow their advice since they may have some insight into the particular likes and dislikes of this particular judge’s courtroom.