A brown wool field jacket and khaki chinos make for the ultimate relaxed style for any man. Rounding off with black leather casual boots is the simplest way to bring some extra flair to this getup. As the weather starts getting warmer, it's time to get rid of those heavy winter clothes and choose an outfit that's lighter, like this one here. All in all, a great choice when it comes to outfit ideas for 30-year-old guys.