Why not wear a polo and navy jeans? These items are super practical and will look amazing worn together. Rounding off with a pair of desert boots is a fail-safe way to bring some extra definition to your getup. When you have one of those bleak autumn days, sometimes only a killer outfit like this one can get you out the door in the morning. So if you're looking for a modern and age-appropriate combination for a 20-year-old man, this is it.