A pulled together pairing of a dark green military jacket and black jeans will set you apart instantly. Rounding off with black suede brogue boots is a surefire way to breathe a touch of sophistication into this outfit. It's is an excellent option when it comes to a killer ensemble that will take you from summer to fall. Gents who wonder how to wear cool casual outfits as you head into your 30s, you have your answer.