Gear up. Wear long pants and sleeves made of leather or another thick, protective material, as well as gloves, eye protection and durable boots that cover your ankles. When it gets colder, don't forget to add layers or invest in heavier gear designed for the temps.
Be seen. Wear bright colors and add reflective elements to both your clothing and bike. Use your headlight, day or night. Ride in the section of lane that makes you most visible to motorists, and if you're not sure a motorist sees you, honk.