The skill of communicating in the highly artificial situations of the modern human! Such crucial skills. Often not taught. Here are the things I use to work on my skills in this area.
Dave Bailey does an executive summary of Marshall B. Rosenberg’s Non-Violent Communication which TBH feels more practical than the original. Also hip: The feedback fallacy:
The first problem with feedback is that humans are unreliable raters of other humans. Over the past 40 years psychometricians have shown in study after study that people don’t have the objectivity to hold in their heads a stable definition of an abstract quality, such as business acumen or assertiveness, and then accurately evaluate someone else on it. Our evaluations are deeply colored by our own understanding of what we’re rating others on, our own sense of what good looks like for a particular competency, our harshness or leniency as raters, and our own inherent and unconscious biases. This phenomenon is called the idiosyncratic rater effect, and it’s large (more than half of your rating of someone else reflects your characteristics, not hers) and resilient (no training can lessen it). In other words, the research shows that feedback is more distortion than truth.
Back and Back’s classic (and very cheap) Assertiveness at work has useful practical exercises. I buy these in bulk and give them to friends with workplace friction challenges.