If it's ease and practicality that you appreciate in an ensemble, wear a crew-neck t-shirt and white and black chinos. A pair of grey athletic shoes easily ramps up the appeal of your look. Gents who are curious how to sport modern casual style as you progress through your teens, you have your answer.
If you'd like take your off-duty game up a notch, consider pairing a crew-neck t-shirt with white and black chinos. You could perhaps get a little creative with footwear and dress down this look by rounding off with white athletic shoes. This is an outfit you, as a teenage boy, can always count on.