A crew-neck sweater and a white and navy long sleeve t-shirt are both versatile menswear must-haves that will integrate really well within your day-to-day off-duty routine. Introduce a pair of dark brown leather derby shoes to the mix for an added touch of style. Stick with this one if you're on the hunt for a neat summery outfit. When it comes to fashion tips for over-30 gentlemen, this outfit is perfect.