First: Use the frontend-design skill for design principles and anti-patterns.

Perform a meticulous final pass to catch all the small details that separate good work from great work. The difference between shipped and polished.

Pre-Polish Assessment

Understand the current state and goals:

Review completeness:
- Is it functionally complete?
- Are there known issues to preserve (mark with TODOs)?
- What's the quality bar? (MVP vs flagship feature?)
- When does it ship? (How much time for polish?)