For practicality without the need to sacrifice on fashion, we like this combination of a brown plaid blazer and blue jeans. If you need to easily elevate your look with a pair of shoes, complement your look with dark brown leather chelsea boots. There's no better way to spice up a dull autumn afternoon than a knockout look like this one. When it comes to dressing ideas for 20-year-olds, this getup looks great on most gentlemen.