You could wear this speckled donegal tweed to either. Suit, $2,695, shirt, $425, and tie, $145, by Simon Spurr. Shoes, $1,250 by Tom Ford. Socks by Smart Turnout. Glasses by Blind Eyewear.

The Donegal tweed suit: Calvin Klein Collection. With this sharp-looking suit, designer Italo Zucchelli shows he's as adept at trad as he is at tech. $1,795, ...