When you have heard a story being told and you want to improve the telling, start by saying ”The clearest picture in the story was …”
Then say something positive about the way it was told.
Then say what you think the story was about. It is important here, that it is your suggestion, not the truth! Please don’t sound like you are an expert and that you are very clever, If you do, it is a direct way to raise resistance to your feedback. You are not clever, you are just a listener and you have some ideas, but it can only work, if the storyteller finds a way to make these ideas their own. You have to give them the opportunity to see the story improve. When you tell a story, it will only work, if there is a partnership between the storyteller and the listener. Likewise in a coaching session there must be a partnership between storyteller and storycoach.
The final thing to identify is ”which part of the story needs some more love!” Then discuss where the storyteller was absent, not grounded, lost in details etc. Then the story coach and the storyteller work together to improve the story and the telling of it.