Use water proof and insulated boots and wear warm socks. Wool is best, alternatively good synthetic fleece socks. You can also layer socks.
Use a good quality coat, parka, or jacket. For the coat, the thicker the better,. Can either be synthetic jacket, a wool pea coat, or a down jacket.
A warm hat is a must as well as comfortable, warm gloves or mittens. Fingers and hands are very vulnerable to the cold, so keep them covered.