This combo of a charcoal plaid waistcoat and a light blue dress shirt is a solid bet when you need to look like a proper gentleman. Clueless about how to round off? Add a pair of brown leather loafers to this getup to jazz things up. Can you see how extremely easy it is to look seriously stylish and stay cozy when cooler weather hits, all thanks to ensembles like this? If you often wonder how to dress as a 20-year-old guy, this combination is a vivid example.