Generate a full detail guide on conducting effective performance reviews. The guide should be structured and empathetic. It must include sections on: 1. How to Prepare for the Review: Gathering Data and Examples. 2. A template for structuring the conversation, including employee self-assessment. 3. How to deliver constructive feedback without demoralizing the employee. 4. A guide to collaborative goal-setting for the next period. 5. Common mistakes to avoid. Please include a disclaimer about consulting HR policies.