Modern pattern mixing works best when the patterns are of different scales. A solid navy, gray, or khaki suit is the perfect complement to this spread-collar cotton shirt and plaid cotton tie. Shirt, ...

In the dead of winter, a dark V-neck sweater beneath your gray suit will make you even sharper than the guys with ties on, inside the office or out. Wool suit, $2,440, by Louis Vuitton. Sweater, $305, ...