Don't run alone on secluded trails. If you slip or fall and injure yourself you could be left helpless. Stay in well-lighted areas along main streets. Run facing oncoming traffic and wear reflective clothing. Stretch well and spend extra time warming up.
Cold temperatures make for tighter, less flexible muscles.
Don't worry about mileage. Set a time and adjust the intensity of your workout. Shorten your stride and keep your feet closer to the ground. This will improve your footing on icy surfaces to decrease your bounce and maintain control. Choose to run over snow rather than ice.