For a look that's city-style-worthy and effortlessly sleek, wear a brown suit and a crew-neck t-shirt. For something more on the sophisticated end to complete your look, introduce black leather chelsea boots to the equation. So if you're scouting for an ensemble that's on-trend but also entirely season-appropriate, this one is great. Take inspiration from combos like this if it's time to add more gravitas to your 20-year-old's look.