Most importantly, take responsibility for yourself and make it clear that all participants should do the same. Each person is responsible for their own life, experiences and behaviour. This extends to taking responsibility for one's participation at a demonstration, protest or rally.
This means taking on any legal ramifications for your actions, and making sure you have made yourself known to the legal support team if you have any concerns about getting involved in arrestable actions.
In an action, it can also mean informing others around you of any relevant medical details, pointing out any dangers, being sure that people standing with you have heard police warnings or are informed of any developments. Fundamentally it means owning your action and choices.
Respect others - ensure your actions are not going to harm, degrade or endanger other people taking part in actions, or innocent bystanders.
Don’t forget to be aware of and respect the environment around you too.