The silliest thing one can do is to behave in a confrontational manner, shout abusive messages and refuse to follow sensible instructions. This will often lead to further calamities. Remember that the police have very wide powers of arrest, and this was the case even before the new Criminal Justice Act was passed. Some police officers have a dislike of demonstrations or cyclists, and will try to sabotage it. Don't give them any extra reasons for doing it.
Pedestrians are our friends, and many pedestrians are supportive of our aims.
It is very important that we do not alienate them by cycling on pavements or going through pedestrian crossings. It is also a good idea to hand out leaflets to pedestrians to let them know why we are there, and to be generally cheerful. In response, CM will often find pedestrians supportive. Buses are also our friends. A proper public transport system is essential to reduce the number of cars on the roads.