Take the initiative. A good action is one that either they cannot see coming, or if you chose to inform your opponents of your general plans, one that is impossible to stop. Clarify each person's acceptable level of risk without machoism. Make sure each person is in a role that relates to their risk level. Train for those roles.
Role play situations so that people know how to respond.
Think through all contingencies and clarify that people know how to deal with them. Make sure people understand legal issues, have a legal phone line in case of arrest. Make sure everyone knows what to do in the face of violence. Build trust in the group, a sense of community is the best antidote to fear. Plan your logistics - the practical issues like transport, equipment needed, communication lines, food, shelter, where to group and regroup.