Consider teaming a black crew-neck t-shirt with tobacco chinos for an off-duty and fashionable outfit. Make black leather loafers your footwear choice to avoid looking too casual. Take cues from outfits like this if you're looking to add more gravitas to your look.
A black crew-neck t-shirt and tobacco chinos are the kind of a fail-safe casual combo that you need when you have no time. Stick to a classier route in the footwear department with a pair of dark brown leather oxford shoes. This outfit is most probably exactly what you've been looking for as a 30-year-old.