For an outfit that's very straightforward but can be manipulated in a multitude of different ways, opt for a black and white crew-neck t-shirt and black jeans. To introduce a little fanciness to this ensemble, add chelsea boots to the equation. A kick-ass combination like this one is just what you need come baking hot summer days. This combination is a striking example 40-year-old guys can very well slay in the style department.