Achieving a hip combination between a dress and a cardigan is tricky for several reasons.
It’s easy to fall into the old fashioned trap. To be on the safe side consider three main things: a sleeveless dress to avoid lumpy shoulders, a V neck cardigan that will not interfere with the neckline of the dress, and a dress with a hemline above the knee. A belt on top of the cardigan will be the defining accessory! You have just strike up a fabulous outfit by experimenting with your classics.