For something on the casually cool end, consider teaming a crew-neck t-shirt with black chinos. Multi colored athletic shoes will bring a more laid-back feel to an otherwise mostly dressed-up outfit. During the winter months, when warmth is critical, it can be easy to surrender to a less-than-stylish ensemble. But this ensemble is a practical illustration that you can actually stay toasty and remain equally stylish during the winter months. And if we're talking casual dressing ideas for 30-something guys, this getup is ideal.