If you like relaxed casual combinations, then you'll love this combo of a crew-neck sweater and light blue jeans. Go ahead and complete your getup with a pair of black leather sandals for a mellow touch. Clearly, it's easier to work through a boiling hot hot weather afternoon in a breezy outfit like this one. If you often wonder how to dress as a 20-year-old guy, this getup is a good illustration.