My Wardrobe features this long cardigan by Helmut Lang. I like how it is styled here. Care for this item is crucial, however, because it is made of wool.
To finish these looks, try some platform shoeties, monochromatic jewelry, such as black and white or any color really, as long as you keep it to one color with black and white. A small clutch with the eye catching knitted dress above will work, and a oversized handbag with the long cardigan would be fine. I would opt for a bright bag for both since these looks are mainly focusing on black, white and grey.