Wear a well-fitted suit. Go for classic colors such as a solid or subtly striped navy or charcoal grey suit or black. Conservative shirts such as a solid white or light blue, pink will work fantastically. Pairing ties will put you in good standing. If you really want to stand out, opt for a solid white pocket square and wear it with a squared fold, with just the edges showing at the top. Remember, you are trying to gain a prospective client's trust. Dressing well will take you a long way.