The goal is to blend in. You don't want to stand out or call attention to yourself. Do not wear sneakers, hats, trendy or revealing clothing, or excessive amounts of jewelry. Extreme hairdos, excessive make-up, and a lot of perfume, cologne or aftershave are not recommended. Be conservative. Dress as though you are going to an important job interview.
For women, wear a suit, dress, or blouse and skirt. Do not wear sandals or open-toed shoes. Wear a bra and pantyhose. For men, wear a suit, or jacket with nice slacks and a tie, or (if you don't own a jacket) a shirt and tie with nice slacks