Give Feedback like a Coach. Consider giving peer feedback like a coach coaches an athlete, focusing on the impact and what's in it for them.
Good coaches closely observe the behaviors that lead to good and bad outcomes. Then they give simple, concrete behavioral tips and explain why those tips will create better outcomes.
Their tips are:
“I watched your last five holes. Four out of 5 tee shots went to the right. Let’s look at your swing over the next three holes... Okay, I noticed you’re coming over the top. If you think about swinging along a single plane you may see that your shots are less likely to hook right.”