This pairing of a white crew-neck t-shirt and black jeans is on the casual side yet it's also sharp and truly dapper. Introduce yellow canvas low top sneakers to the equation et voila, your ensemble is complete. As you can see, it's extremely easy to look dapper and stay comfortable when chillier weather arrives, all thanks to getups like this one. Wondering how to perfect casual outfits in your twenties? This combo is the perfect answer.