Pair a blue denim shirt with blue jeans if you're searching for an outfit option that is all about relaxed casual cool. A nice pair of black chunky leather derby shoes is an effortless way to inject a dash of polish into this look. As you can see here, this getup is a really wonderful choice, especially for transitional weather, when the temps are dipping. When it comes to casual fashion tips for teen guys, this look looks cool on almost anyone.