You can keep your Patagonia puffer and your cushy Ugg boots, but if you really want to dress like a "rich mom" who owns a cabin in the mountains, it's time to add a Fair Isle sweater to your wardrobe.

Few sweaters are as quintessentially “winter” as a Fair Isle sweater. The traditional knit, best recognized for its multicolored, geometric pattern that begins under the collar, originates from a ...