"Tell me one thing about your bars routine that made you happy. Tell me your favorite part of your floor routine today. What made you most proud on beam? What was your best part of vaulting today?" Then "And those things are making me smile today, so thank you for making Mom smile!"
My dd is not a top of the podium type of gymnast. (Although she did get first once on beam!) She's very middle of the pack, or bottom of the pack on vault. We learned though her 6 years of competition dance that judges are human, too, and have very different biases and preferences when judging. We learned to focus on what she did well. Now that she's 12, sometimes we talk about what she could have done differently. She's old enough, and knows enough about skills and her routines, that she usually knows exactly what she should have done to score higher. And if she can't figure it out, then we shrug and figure either the judge likes a different style, or her coach will tell her what she needs to change.
When she was 8, I steered the conversation toward what she did well, not the negative side. In our situation, that's the teacher's/coach's job.