A navy long sleeve t-shirt and white chinos have become must-have closet pieces for most gentlemen. Dial down the casualness of this outfit by wearing a pair of derby shoes. As the weather starts getting warmer, it's time to shed those heavy winter gear and opt for a look that's lighter, like this one here. Those who are curious how to sport semi-casual outfits as you work your way through your 20s, this outfit should answer your question.