- hold your line and ride a steady pace - don't wiggle all over the place and surge/brake. try to be steady both fore/aft and side to side

- to repeat - don't brake in paceline - anticipate changes in speed and leave enough room to modulate your speed gradually by backing off your pedaling or sitting up. of course you have to brake if the person in front of you does, but try not to bake hard/suddenly/for no apparent reason - you could get rear-ended, and it's the person in back who usually falls

- don't overlap wheels, i.e., ride half-next-to someone. - you should be nearly completely next to them or completely not next to them

- signal your intentions - simple pointing in the direction you are moving is fine, holding your hand down and out to the side with the palm back to signal stopping

- don't cut people off, make sure it's clear behind you before you move to the side

- if there's a road obstacle that everyone is going to need to avoid, point down and to the side that the obstacle is on, well before you get to it

- smile and chat!!!

everything else is just common sense politeness or too complicated to explain, but the stuff above should keep you from making anyone crash.

Have a great ride!!!!!