Reach for a navy long sleeve shirt and black jeans for a city casual and trendy ensemble. Rounding off with a pair of black leather chelsea boots is a fail-safe way to bring a touch of refinement to your ensemble. As you can see, this outfit is a striking illustration that good style and dressing warmly for the winter season are not mutually exclusive. This outfit demonstrates that transitioning from your 20s to your 30s is no reason to shed casual style altogether.