Adding cardigans to your professional wardrobe is a good idea. It’s very simple to add a cardigan to a woman’s business suit. Cardigans are usually not so bulky that it looks weird wearing it under a suit jacket. One of the most chic ways to wear a cardigan is to have a basic, white blouse under the cardigan, with the collar sticking up and folded over it. A basic blouse, in traditional white or other color, gives a classy feel to any work outfit. In normal weather, you may have your classic business suit with a white blouse, but in chilly weather you just add a cardigan over the blouse, and it looks quite polished while keeping you warm at the same time. And in order to get maximum warmth, get a wool blend. If the cardigan is going to be thin, so as to not bulk under the suit jacket, it should be as warm as possible and then your best bet is wool. Or cashmere.