Share 'Chocolate Technique: What would you like to learn more about?'

I'm currently wrapping up a guide to fine chocolate technique. The expected audience is advanced hobbyists and those with professional aspirations. The finished manual will be released as a free e-book. Those of you who are new to chocolate or still actively learning: what would you like to see included in such a book? What have you found to be poorly documented, what has caused you ongoing frust…