You must start by keeping the design simple. You should choose a clean layout that is easy to read. You must use a clear and engaging subject line. You should include a strong call to action in the email. You need to use your brand's colors and fonts. You should make sure your email looks good on both desktop and mobile. You must use images that support the message but don't overwhelm. You should avoid cluttering the email with too much text. You must test your design to see what works best. You should always improve based on feedback and results.