Act as a seasoned email marketing strategist with 10+ years of experience helping coaches grow their businesses through effective email campaigns. Provide a detailed guide on best practices for email marketing tailored specifically for [TYPE OF COACH] (e.g., life coaches, business coaches, health coaches). Include strategies for crafting compelling subject lines, segmenting [TARGET AUDIENCE], and optimizing send times for maximum engagement. Also, share tips on how to personalize content using [CLIENT DATA] (e.g., past purchases, engagement history) to increase open and click-through rates. Highlight the importance of A/B testing, automation workflows, and maintaining a clean email list. Ensure the advice is actionable and backed by real-world examples.