Constructive Criticism: A Handbook Speaking & Listening More Effectively in Personal Relations, Groups, & Political Activities By Vicki Legion (Gracie Lyons), 1976
Constructive Criticism is a wonderful example of the blending of valuable and powerful socialist theory with a practical, down-to-earth pragmatism. The result is an extremely useful manual for people who work together for positive social change. Putting Gracie Lyon's suggestions into practice will increase the power of people's work as well as their personal sense of well being and satisfaction.
eBook: https://www.marxists.org/history/erol/ncm-3/constructive-criticism.html
PDF: https://frauenkultur.co.uk/wp-content/uploads/2020/05/Constructive-Criticism.pdf
Audiobook: https://youtu.be/rvTByQIQAxQ
Good thread
Another rule of thumb: it's good to give people an out, i.e., be respectful and charitable enough that they can leave the conversation at any time without feeling they need to defeat you to save face. It's as much for your own sake as theirs. If they feel like they have to defend themself by attacking you, then suddenly you're in the same position of having to defend yourself and no one has an off ramp.
Sometimes easier said than done, but it's never too late to deescalate even if it does start to get heated. It's just harder.
It also helps with persuasion. No one wants you to be right if it hurts them. Respect and patience gives them emotional space to consider your ideas, whereas hostility gives them an incentive to shoot you down reflexively as a way to defend themself.