For an outfit that's super straightforward but can be flaunted in a myriad of different ways, team a black crew-neck t-shirt with skinny jeans. When it comes to footwear, complement this outfit with athletic shoes. No doubt, it's easier to work through a blazing hot summertime afternoon in a breezy look such as this one. Overall, a good demonstration of relaxed casual fashion for men in their 40s.