You can look amazing without exerting much effort by wearing a grey crew-neck t-shirt and black jeans. Complement your ensemble with white and black athletic shoes to add a dose of stylish nonchalance to your ensemble. You'll always look stylish even despite the sweltering heat if you keep this look as your go-to formula. Off-duty outfits for stylish gentlemen in their 40s aren't actually that hard, as you see.