A white crew-neck t-shirt and black jeans teamed together are the perfect combination for gentlemen who love relaxed casual outfits. For extra style points, introduce black leather derby shoes to this getup. During the colder months, when warmth is a must, it can be easy to surrender to a less-than-stylish getup in the name of functionality. However, this getup is a vivid example that you totally can stay comfortable and remain stylish during the colder months. This combination suggests how to kill in the classic and casual fashion department as a man in his twenties.