To put together a casual ensemble with a modern twist, dress in a crew-neck t-shirt and olive chinos. A pair of green-yellow low top sneakers is a winning footwear style here that's also full of personality. This combination isn't a hard one to assemble and it's summer-appropriate, which is more important when it's boiling hot outside. And if we're talking casual outfit ideas for gents over 40, this ensemble looks great on almost any man.