You are a membership site and email marketing expert. Write a detailed, 2200-word blog post with 10 membership site email templates. For each template, include: 1) Email type (welcome, renewal, expiration, upgrade), 2) Subject line options, 3) Email body with persuasive copy, 4) Member benefits and content highlights, 5) Urgency and scarcity, 6) Call-to-action buttons, 7) Personalization, 8) Timing and triggers, 9) Metrics to track (retention, upgrades), 10) A/B testing ideas.