Confessional Etiquette

The new priest is nervous about hearing confessions¹, so he asks an older priest to sit in on his sessions. The new priest hears a couple confessions, then the old priest asks him to step out of the confessional for a few suggestions.
The old priest says, "Cross you arms over your chest and rub your chin with one hand."

The new priest tries this. The old priest suggests, "Try saying things like, 'I see,' 'yes,' 'go on,' 'I understand,' and 'how did you feel about that?'"

The new priest says those things, trying them out. The old priest says, "Now, don't you think that's a little better than saying, 'Whoa... What happened next?'"