For an outfit that's super easy but can be flaunted in a variety of different ways, make a navy long sleeve shirt and black jeans your outfit choice. Add a pair of low top sneakers to your ensemble and ta-da: your getup is complete. When temps are getting lower and autumn is setting in, you'll love this combo as your uniform for in-between weather. And if we're talking casual clothing for 30-year-old gents, this look is a good look on almost any guy.