Stay in your lane - Staying on the correct side of the centerline is not just a good idea, it's the law. There is never a reason to cross the centerline. This action is 100% reckless and is plain stupid. A quick “on your left” will usually clear the way for you to pass safely without crossing the centerline.
Warn others of hazards - Communicate verbally or through hand signals any road debris, approaching vehicles or other hazards. It's the right thing to do.
Be respectful - In the absence of a designated bike lane it’s always safer for you and the group to ride single file.
Don't Abandon Riders - This is a recipe for disaster. That person you left behind may need help with a flat, not know the route back, have an accident. The possibilites are endless. Don't contribute to them.
Don't Half Wheel - The right way to ride in a double paceline is handlebar-to-handlebar, not half a wheel ahead of the rider next to you. Half-wheeling pisses people off, especially when you accelerate to maintain the half-wheel advantage despite your partner’s attempt to pull even with you. It also messes up the spacing for everyone in the paceline behind you.
Don't Run Red Lights - Besides being unsafe, against the law, and damaging to our collective reputation, it’s also disrespectful to all the groups who are working hard to convince communities to improve cycling infrastructure and enhance cyclists’ safety.