1. Use Inline CSS: Many email clients do not support external style sheets. Using inline CSS ensures that your styles are applied consistently across all platforms. 2. Avoid Unnecessary Code: Remove any redundant or unused code. This helps keep your email lightweight and easier to manage. 3. Validate Your Code: Use tools to validate your HTML and CSS to catch any errors or warnings. 4. Comment Your Code: Adding comments can help you or anyone else understand the structure and purpose of your code, making it easier to maintain. 5. Test Across Clients: Ensure your emails render correctly by testing them across different email clients and devices.