This relaxed casual pairing of a black turtleneck and black leather jeans is extremely easy to throw together without a second thought, helping you look seriously stylish and ready for anything without spending a ton of time digging through your closet. Take a classier route on the shoe front by sporting a pair of black leather casual boots. When you have one of those dreary fall days, sometimes only a kick-ass getup like this one can spice it up. Gents who are curious how to wear smart casual outfits as you go through your 20s, you have your answer.