Over at 101 Books (writer/blogger Robert Bruce is reading all 100 of Time Magazine‘s greatest English-speaking novels since 1923), he posted novelist Jonathan Franzen’s 10 Rules of Writing.
While these are not specifically screenwriting-related, there’s certainly some crossover. I especially like #6 since some often misinterpret the suggestion to “write what you know”…
6. The most purely autobiographical fiction requires pure invention. Nobody ever wrote a more auto biographical story than “The Metamorphosis”.

