A white and navy plaid long sleeve shirt and black jeans are wonderful menswear must-haves that will integrate perfectly within your casual fashion mix. A pair of grey canvas high top sneakers instantly ramps up the style factor of this ensemble. No doubt, it's easier to work through a warm summertime day in a easy and breezy combination like this. This outfit illustrates how to dress stylishly and look good as you make your way through your 20s.