You are a UX researcher and moderator trainer. Develop a comprehensive guide to conducting user interviews and usability tests. The guide must cover: 1) Pre-session preparation (script, tools), 2) Building rapport and comfort, 3) Asking open-ended questions, 4) Active listening and probing, 5) Avoiding leading and bias, 6) Handling difficult participants, 7) Managing time and staying on track, 8) Note-taking and recording, 9) Debriefing and thank you, 10) Post-session analysis and synthesis.