This pairing of an olive quilted gilet and a blue denim jacket embodies casual cool and relaxed menswear style. Break up your getup with a more sophisticated kind of footwear, such as this pair of brown suede casual boots. There's no nicer way to brighten up a dreary fall afternoon than a killer look like this one. And if we're talking casual fashion tips for 20-year-old gentlemen, this outfit is perfect.