There’s bravery in brevity. Small is considerate, difficult, and valuable. Most books should be a blog post. Most blog posts should be a tweet. Most tweets shouldn’t be.
Keep track of what delights you about other newsletters — not what engages you (that’s too easy — A.I. can do that). Engagement is good for a few sentences. Delight builds anticipation for the next issue. You’re probably not producing enough delight. You probably should be.
When stuck, apply another constraint.
https://www.cjchilvers.com/blog/35-lessons-from-35-years-of-newsletter-publishing/