The first thirty interns taught me that a review comment without a reason is just an order. 'Rename this' teaches nothing; 'rename this so the function reads like a sentence at the call site' teaches forever.

We adopted three habits: review in person for the first two weeks, always propose an alternative instead of only rejecting, and let interns review each other before a senior looks at it.

Throughput went up, but more importantly the same mistake stopped arriving twice.