Marshall B. Rosenberg
Describe what happened without judging, name the feelings and needs involved, and make a clear request rather than a demand.
Separate your objective observations of a situation from your subjective evaluations to prevent triggering immediate defensiveness in others.
Express true emotional states rather than using feeling words that actually disguise thoughts, accusations, or judgments about other people.
Recognize that all human emotions are directly tied to universal underlying needs that are either being met or ignored.