What are the best practices for creating an effective email marketing campaign?

Clean list + clear value + mobile-first design. That's it.

Absolutely! Clean list is key - make sure your email list is up-to-date and you have permission. Clear value is a must - what's in it for them? Keep the design simple and mobile-friendly since most people check email on their phones these days. Oh, and don't forget to test different subject lines to boost those open rates!