The Emotional Craft of Fiction by literary agent Donald Maas is an excellent book for any writers trying to ensure that their novels have emotional depth and will resonant with their readers at a cellular level. Each section is clearly structured, starting with great examples from literature by authors adept at using the techniques described, and ending with writing exercises that enable you to put this into practice, either through writing something from scratch, or by applying it to an existing work-in-progress.
I found this particular helpful in thinking about whether my characters’ highs were high enough and lows low enough, whether my emotional midpoint was doing what it needed to do and whether my protagonists had coherent emotional journeys running throughout my novel.
The book ends with the extremely handy ‘Emotional Mastery’ checklist, which takes you back to each idea and the page where the tips are, so that you can go through and check you’ve tried what you most need to fix emotional plot problems. I’m sure my writing is stronger as a result and I’d recommend it to anyone trying to craft their own fiction.