If his workplace is really casual, he can swap the button-up shirt for a polo or crisp tee, trousers for chinos or jeans, and an overshirt or sweater instead of a sports jacket. He can add a sleek ...

You can dress 'em up with a button-down and loafers, although if a tee and sneakers are more your vibe, those will look great, too. Stretchier and softer than jeans, these straight-leg pants ...

Discreet Athleisure: You can totally wear yoga pants to the office - just look for wide-legged ... Throw on a knitted top ...