Great video from a screenwriter on using index cards to write a screenplay
Here is the video:
Creative Spark: Dustin Lance Black
I found impressive how he structures everything from the beginning in notecards and has like his own kind of Zettelkästen where he stores a lot of ideas, plots, characters, backgrounds and everything in between. A similar workflow from the one I've seen taken by Ryan Holiday and Robert Greene.
I hope you like it.