We've recently had a workshop on communicating feedback. Another tactic which we didn't cover is Nonviolent communication (NVC). Dave Bailey highlights how to apply NVC effectively:
Without a healthy amount of self-empathy, we often find that our own needs — and the needs of the business — take the passenger’s seat. — Dave Bailey
The trick to NVC is making sure your communication is honest and internally focused. How do you feel about the situation? What unmet needs are driving those emotions? What action can the other person take to help you?
By thinking about and framing your feedback in this way, you are able to build a common understanding.