This pairing of a black long sleeve t-shirt and red sweatpants is on the off-duty side but is also seriously stylish and really stylish. If you're on the fence about how to round off, a pair of athletic shoes is a surefire option. As you can see, this getup is a really smart idea, especially for summer-to-fall weather, when the temps are falling. This combination should erase any doubts you had about wearing casual clothes in your 30s.