Ride smooth. No sudden turns (lane changes), braking, surging etc... Do this and keep your front wheel from touching the rear wheel in front of you and you'll be fine.

Call out any hazards (water bottles, pot-holes, gravel etc.) that you see as a favor to those behind you. Say something like "slowing" if you need to touch your brakes.

If you're near someone who isn't following the principles outlined above, drop back. You don't want to ride near someone you might nickname "Sketchy", "Twitch", or "Silent Dave".

When you get back home, find someone who will teach you to ride a pace line. You're really missing out if you don't partake in that part of the sport.