Ten tips from Academy Award winner Billy Wilder, whose screenwriting credits include The Bishop's Wife, Ocean's Eleven, A Song Is Born and Casino Royale. The list goes on and on, as Billy also directed films like Some Like It Hot, Sunset Boulevard and The Seven Year Itch. So Billy knew his stuff.
1. The audience is fickle.
2. Grab 'em by the throat and never let 'em go.
3. Develop a clean line of action for your leading character.
4. Know where you're going.
5. The more subtle and elegant you are in hiding your plot points, the better you are as a writer.
6. If you have a problem with the third act, the real problem is the first act.
7. A tip from Lubitsch: Let the audience add up two plus two. They'll love you forever.
8. In doing voice-overs, be careful not to describe what the audience already sees. Add to what they're seeing.
9. The event that occurs at the second act curtain triggers the end of the movie.
10. The third act must build, build, build in tempo and action until the last event, and then--that's it. Don't hang around.
Billy also knew how to get the last laugh. :)