This ensemble with a red long sleeve shirt and light blue ripped skinny jeans isn't super hard to pull off and is easy to change throughout the day. When not sure as to the footwear, stick to a pair of athletic shoes. As you can see here, as a teenage guy, you have a vast array of sartorial options.
For a laid-back and cool getup, make a red long sleeve shirt and black skinny jeans your outfit choice — these pieces fit nicely together. If you wish to immediately play down your ensemble with a pair of shoes, why not complement your ensemble with a pair of athletic shoes? Gents who are curious how to rock cool casual outfits as you make your way through your teenage years, you have your answer.