Corey emphasizes the importance of starting any grievance process with the "just cause" principles, especially focusing on whether a rule exists that the carrier violated. He emphasizes that management frequently cites rules that don't exist or don't apply to the situation. Corey encourages listeners to research any rules cited by management to determine if they are legitimate and to use this information to their advantage during grievance procedures. He uses several examples to illustrate these concepts and also encourages listeners to be proactive and thorough in their work as shop stewards.