Wear a black shearling jacket with dark brown jeans to put together a casually stylish look. Why not complete your outfit with a pair of black leather chelsea boots for an added touch of style? In winter, when functionality is prized, it can be easy to surrender to a less-than-stylish look in the name of practicality. This look, however, is a shining example that you totally can stay cozy and remain equally stylish in winter. Getups like this go a long way towards maturing your style as a guy in his thirties.