Choose an olive overcoat and a white crew-neck t-shirt for laid-back sophistication with a masculine take. Loosen things up and complement this getup with beige athletic shoes. Keep this getup in your front hall wardrobe when warmer days are here, and we guarantee you'll save a lot of time getting ready on more than one morning. When it comes to casual style tips for 20-year-old gents, this combination looks great on almost any gentleman.