A grey crew-neck t-shirt and grey skinny jeans are a casual street style pairing that every sartorial-savvy gent should have in his closet. And if you wish to immediately elevate your outfit with a pair of shoes, why not add a pair of dark brown leather casual boots to this look? You bet this combo is great to keep you warm and stylish throughout the winter season. This pairing demonstrates that as a 20-something man, you have a wide range of styling options.