This combo of a black gilet and a grey turtleneck makes for the perfect foundation for a casually cool outfit. Finishing with white leather high top sneakers is a guaranteed way to infuse a touch of stylish effortlessness into this ensemble. So as you can see, it's a neat, not to mention season-appropriate, outfit to keep in your transeasonal sartorial collection. This ensemble illustrates how to score in the casual style department as a 20-something guy.