Consider wearing a brown overcoat and a black vertical striped suit for seriously smart attire. Complement this outfit with a pair of dark brown leather loafers and the whole look will come together. During the winter months, when warmth is crucial, it can be easy to settle for a less-than-stylish look in the name of functionality. This look, however, is a clear example that you can actually stay toasty and remain equally stylish in the winter months. As a man in his thirties, you'll appreciate this ensemble.