Do not hurt the engineer's feelings. Everyone makes mistakes. Always
provide constructive feedback
A review should be a learning process, both for the reviewer and
author. And must not be an ego-battle to prove that one is superior to
other
Code-reviews should be in chunks. This way, it is easier to go through the
code properly and provide helpful feedback, vs reviewing the whole code-base
at once.
Every code piece should be peer-reviewed irrespective of who wrote it. Be it
a senior developer or an intern.
The aim should always be to develop a positive culture around code review.
It should not be a process that scares people away. Instead, it should
help engineers write better code, and work on the feedback received.
Automate review process if applicable. Static Analyzers such as prettier and
ESLint could reduce the time invested in the process by a lot.