A grey print sweatshirt and navy jeans are great menswear must-haves that will integrate nicely within your day-to-day collection. Feeling bold? Change things up a bit by finishing off with a pair of black leather loafers. Keep this getup in your front hall wardrobe come warmer days, and rest assured, you'll save a ton of time brainstorming for what to wear on more than one occasion. This getup is probably exactly what you're looking for as a 30-year-old gentleman.