Trending Mens Casual Wedding Guest Attire Summer : This guide to wedding dress codes is organized by event, formality, and at a more formal beach affair, men's shirts should be of elegant linen or crisp cotton. We have selected 66 great mens summer wedding attire options, that are both stylish and cool, without being stuffy. Mens Casual Wedding Guest Attire Summer : These five dresses are perfect for a more casual indoor or outdoor wedding!