Show off your credentials in men's fashion by putting together a red plaid long sleeve shirt and brown chinos for a casual ensemble. A nice pair of tan athletic shoes is the simplest way to add a dose of stylish casualness to your look. There's no better way to spice up a bleak autumn day than a kick-ass ensemble like this one. Those who are curious how to pull off cool casual style in your early 20s, this combination should answer your question.