Listen to what they have to say, focus on what they are focused on and be as helpful as possible on those topics. Then you are allowed to add ONE thing you “noticed.”

Ie, “I noticed you struggled with serving after you had a big lead in match one. What do you think happened?”

Then if they ask your thoughts you are allowed to provide them. The key is that their tennis game is THEIR job to fix. You are only involved if as and when they want you involved. If you ask good questions, give good advice, and are always supportive, they WILL want you involved. Unless they don’t care. Which happens. In which case you could give your opinion that they ought to try caring a little—but only one time.

Honestly it sucks lol. But this is what I’ve learned.