Invest in a front headlight for your bike to increase your visibility. Don't just rely on streetlights--you wouldn't drive a car at night without headlights, would you? You may also want to invest in reflective gear so other drivers can see you.
Don't Stop in a Car's Blind Spot.
It's called a blind spot for a reason. If you're riding on the road and come to a red light or stop sign, stop behind the car in front of you (unless you are in a separate lane). If you stop in the vehicle's blind spot, only the most alert of drivers will recognize your presence. Virginia (and most other state) laws require bicycles to obey all traffic signs, signals, lights and markings.
Wear Something Bright, Even During the Day.
Let's face it: you're a lot smaller than most of the other things on the road. Make sure they can see you coming.
Signal Your Turns.
You're less likely to be hit if others on the road can easily predict your actions. To signal LEFT, point your left arm straight out. To signal RIGHT, point your right arm straight out. You may have learned to signal a right turn by bending your left arm, but most drivers have no idea what this means.
Ditch the Blackberry.
You're not supposed to drive and text, so why would you try to balance it (literally) with biking?
The Washington, D.C. Court of Appeals recently ruled that riding a bike IS operating a vehicle, and thus a biker could be charged with a DUI/DWI. Most state laws also have a broad definition of what constitutes operating a vehicle.
Sometimes, even if you have taken all the appropriate precautions, accidents still occur. If you are involved in a bicycle or pedestrian accident, please see my other guide, "What to do in a Bicycle Accident," and seek the counsel of an experienced attorney.