Here I'm going to depart from my mystery DEATH IN THE CHAVURAH and apply the exercise from Laura Whicomb's book NOVEL SHORTCUTS to two different teen novels I have written but am considering revising.
The first is an urban fantasy called TEEN TIME WITCH. Currently, it's structured by having a quote about time open each chapter. Here's some additional ideas based on Whitcomb's exercises:
1) As a cautionary tale:
Open the book with a caution: "You know how your mom tells you not to get involved with a boy (in that way). Well, she knows what she's talking about it. Because it releases all sorts of powerful feelings. In my case, it brought out my powers."
Because TEEN TIME WITCH involves a prophecy where time starts to run backward until it ends, I could show the time at the beginning of each chapter, and the reader can see how it goes backward.
3) Illustrating a story
A witch's spell could start each chapter or a how-to tip on how to be a witch.
4) Diary format
Main character Eve writes down in her diary as events occur; might lead to a new title DIARY OF A TEEN TIME WITCH which might have appeal
Let me know which sounds like the most compelling device to you and/or the one that might best catch the interest of agents or editors.