26. The Tailored Wool Suit — The best thing about this trend is that it's really a twofer— you get a blazer and pants that can seamlessly fit in with most of your wardrobe. Wool will keep the chill at bay, and we're all about oatmeal, rich grays, and heather when it comes to hues. Of course, don't even think about going a size up — don't be spooked by a fit that shows off your shoulders.  

SuitSupply Washington Brown Plain Suit, $469, available at SuitSupply; Ted Baker similar styles (prices vary), available at Ted Baker.