How to write a great film script by understanding genre

Most screenwriting how-to books, I find, are more or less the same, and I try to use their methods on a “whatever works” basis. Most intermediate level writers – who’ve demonstrated some general capability but are still finding that killer script elusive – really need some deeper insights into genre, not another lesson in a new way to slice the screenwriting onion. For more work on genre, I highly recommend the Creative Essentials series from Kamera Books:
http://www.kamerabooks.co.uk/creativeessentials/index.php?link1=home

For general lessons, I may never read another how-to book again, since happening upon my fellow blogger Craig Lumen.