A burgundy sweater vest and a white and black vertical striped long sleeve shirt make for the ultimate casually sleek outfit. Finishing with a pair of black leather low top sneakers is an effective way to introduce a hint of stylish casualness to your getup. It's a wonderful idea when it comes to planning a kick-ass outfit for in-between weather. Take cues from combinations like this if it's time to add more gravitas to your 20-year-old's look.