Wear a black and white print hoodie with a black crew-neck t-shirt for a city casual outfit that's easy to put together. And if you wish to immediately dress down your ensemble with one single item, opt for a pair of grey athletic shoes. When it's one of those dreary fall days, sometimes only a knockout getup like this one can spice it up. Those wondering how to rock modern casual dressing as you make your way through your 20s, this combination should answer your question.