This combination of a biker jacket and grey jeans is on the casual side but also ensures that you look dapper and truly stylish. Let your styling credentials really shine by finishing this ensemble with a pair of brown leather casual boots. As you can see here, this ensemble is a really great pick, especially for awkward transition weather, when the temps are starting to drop. This outfit shows that as a 40-year-old guy, you have a wide range of dressing options.