1. Get a soft-shouldered cotton sports jacket. I buy them whenever I see them. They’re pliable, comfy, and easy to pack. They do the job of a sweater but look dressier and have lots of pockets.

2. Cashmere sweaters, especially V-necks. Can’t have enough of those, whether they’re four figures from Hermÿs or two figures from Uniqlo. I actually once noticed a stylish Uniqlo salesman wearing two at the same time, in lime and in sea blue. A great look.

3. Good chinos or sporty flat-fronts are a must. Maybe my best casual pants are Helmut Lang from back when there was a Helmut Lang.

4. The button-down-collar oxford cloth shirt.

Glenn O’Brien on mastering business casual.