Stop at stop signs and red lights. Foot down stops are safest, rather than trying to balance the bike while stopped. There is safety in numbers. A pack of 10 riders is safer than a solo rider due to high visibility and the lower likelihood of aggressive motorists pulling stupid maneuvers. Conversely, a large pack should not hog a large chunk of the road.
Single file is best on a busy or narrow-shouldered road.
Also, there are much better resources in a group in the event of a mechanical failure or health problem. Ride with authority and steadiness. There is nothing more irritating than a meandering cyclist riding unpredictably along the road. Plus, wobbly riding adds time and effort to the bicycle leg in the races. This encourages better treatment of cyclists and leaves a positive taste with them.