Pull over as quickly, safely and carefully as possible.
Safety first. No matter what, you want to be as polite to the officer as you can. Part of this means pulling over as far to the side as possible. They don't want to worry about dodging traffic as they approach your car on foot. And the quicker you respond to their sirens, the more cooperative you appear to be.
Await the officer's instructions.
While you want to be cooperative, don't take it too far. Immediately digging for your license and registration implies that you "know the drill." This tells the officer that you've been her before, and makes you look a little suspicious. Just do what they tell you to do, when they tell you to do it.
In Virginia, you are required to have your license, vehicle registration and proof of insurance available. If you need to get any of these items out of your glovebox, let the officer know before you reach for it. You should make sure they can see your hands (and any passengers' hands) at all times.
Don't admit fault.
Inevitably, the officer will ask if you know why you're being pulled over. Before you spit back a quick answer, stop and think. The best answer is more likely "no sir," or "no ma'am." Fighting a ticket becomes far more difficult when you've expressed guilt.
Just sign the ticket.
If the officer ends up giving you a ticket, sign the where he or she asks you to do so. Signing the ticket is not an admission of guilt. Remember, you need to be polite even if you disagree with the charge. It is far better to contact an experienced attorney and let them handle the case than dispute the charge with the officer.