newsletter-subject-lines

Installation
SKILL.md

Newsletter Subject Lines

Write subject lines that get opens.

Core Philosophy: 80% of email performance comes from the subject line. Generate 10+ options, evaluate systematically, select best.

Key constraint: 35-50 characters ideal (mobile preview). Be clear even when truncated.


The 3-Phase Workflow

Phase 1: Identify Core Value

What's the one thing that makes this newsletter worth opening?

Installs
22
GitHub Stars
4
First Seen
Jan 27, 2026
newsletter-subject-lines — cdeistopened/opened-vault