A blue long sleeve shirt and light blue jeans are the kind of a fail-safe casual look that you need when you have no time. A good pair of derby shoes is the simplest way to bring an extra touch of class to your look. And if you're looking for a knockout outfit that will take you from winter to spring, this one is great. Those who are curious how to wear semi-casual outfits as you work your way through your teens, this combination should answer your question.