A black turtleneck and charcoal sweatpants are the kind of a fail-safe casual look that you so awfully need when you have no time to dress up. On the shoe front, go for something on the casual end of the spectrum by finishing off with a pair of grey athletic shoes. So when summer is done and autumn is settling in, you'll find this look to be your everything. And if we're talking casual outfit ideas for young guys, this combo looks great on almost any guy.