Go for a straightforward but casually cool option by teaming a dark green long sleeve shirt and black plaid chinos. Rounding off with a pair of brogues is a surefire way to breathe a touch of class into this outfit. This getup isn't a hard one to score and it's season-appropriate, which is important when it's extremely hot outside. If you want people to see maturity in you as a young adult, a look like this is what you're looking for.