This book (must download the PDF, the view link appears broken) has an intriguing section on crafting for each story (rather than a general overview of how to craft) in the Story Training for Trainers manual. It focuses on specific language and concept issues within the story. The handbook actually has pre-crafted all the stories ready for use (similarly to almost all other resources) I feel this is a shame as half of the benefit of crafting the story is knowing the passage intimately.