Practice giving feedback
To make it easier, you don’t necessarily have to get better at saying the exact right thing. you just need practice. If you see someone doing something they can improve, offer your observations right away. Don’t wait until your next meeting to provide your input; give it in the moment.
Most importantly you want as little time as possible between identifying and discussing the problem. After you address the problem, offer a “patch up” to help them know that you respect them.
Convey the motive
The biggest predictor of whether someone will become defensive after presented with feedback is the motive behind it. If they know that you’re trying to help them and hold them accountable, they are less likely to push back.