here's some ideas, based on all the rules i've violated:

- tell them to drink water after they've come off the line and are heading back
- tell them to set a policy that they will always pass other riders on the right, left, etc so the pack doesn't shatter every time there's someone else in the road.-
- give them some measurable way to keep pace. constant pedal pressure, constant perceived effort, etc.
- make sure they know not to speed up or slow down too much at hills so the pack stays together
- try having the last person yell "rotate" when they reach the back so the next guy knows to go.

also, yelling out hazards is great, but i find that when i ride with non-racers, they tend to OVER-call at the beginning of the ride (which is annoying) and then not call out things towards the end when they get tired.