For a laid-back and cool outfit, pair a crew-neck t-shirt with charcoal jeans — these pieces go really cool together. On the fence about how to round off this look? Rock grey slip-on sneakers to polish it off. As you can guess, this is a killer pick come warmer weather. Think it's hard for gentlemen in their 40s to nail edgy casual outfits? This pairing is irrefutable proof of otherwise.