Here's what have been working well for me. I wear dress pants (not jeans, not chino - Izod for example), colorful shirts (Nautica are my favorite) - always tucked in, good looking but comfortable shoes (not sneakers). I make sure they are always reasonably ironed. And silly socks - Happy Socks are the best. During the summer I use short sleeves, long sleeves in the winter if I feel like. I never use a tie, but you may if you feel like.