[coredog64]

One good rule I was given by a tech lead is to not use the word "you" in the PR comments. PR comments are a discussion on the failure of the code, not of the individual. Avoiding "you" allows for some separation between the two.

[cachemiss]

I always use "we", and I almost always phrase things as a question.

Example: "So we are doing X here, which I think will probably do Y, which could have adverse affects Z, are we sure we want to do this?"