Code Review Guidelines

TL;DR

Seek to understand the context of the change (what, why, and how).
Seek to understand the author’s perspective.
Check out the branch and test the changes locally on your own.
Consider using the Conventional Commenting style to better convey your intent.
Try to be thorough in your reviews to reduce the number of iterations.
Ensure the author is clear on what is required from them to do.
Communicate which ideas you feel strongly about and which you don’t.
Offer alternative implementations, but assume the author has already considered them (ask questions).
Look for opportunities to simplify the code and improve its readability.
If you don’t understand a piece of code, ask for clarification (other people might have the same question).
It can be helpful to post a summary comment after a round of review comments.