Pairing a navy polo neck sweater and dress pants is a guaranteed way to inject refinement into your wardrobe. For something more on the off-duty side to complete this ensemble, complete your outfit with a pair of white canvas low top sneakers. With the departure of winter come warmer days and more sunlight and the need for a light and breezy outfit just like this one. Definitely a foolproof choice when it comes to outfit ideas for guys in their thirties.