A dark green long sleeve shirt and dress pants are a polished look that every smart man should have in his closet. In the footwear department, go for something on the smarter end of the spectrum by slipping into a pair of brown leather oxford shoes. When it comes to dressing for fall, nothing beats a kick-ass combination that transitions easily between seasons. When it comes to fashion tips for 30-year-old gents, this ensemble looks nice on most gents.