If the situation calls for an effortlessly classic look, you can go for a navy vertical striped suit and a dark brown turtleneck. To give your overall ensemble a more sophisticated finish, introduce brown leather double monks to the mix. Keep this combination in your front hall closet when warmer days are here, and we promise you'll save time planning what to wear on more than one morning. This combination shows that dressing cool as you step into your 30s is not that daunting a task.