This pairing of a blue hoodie and charcoal sweatpants is the perfect base for a casually cool outfit. Avoid looking too casual by rounding off with brown leather low top sneakers. As you can see, it's very easy to look amazing and stay warm come colder days, all thanks to getups like this one. Those who wonder how to rock cool off-duty style as you make it through your 20s, you have your answer.