There's only one story to tell

For writers,

When coming up with a screenplay, just remember that change always makes for a good movie. The purpose of a film to make the main character change over the course of the film. They start in one direction and throughout the film we see the decisions that they make and the changes that effect them to mold them into a completely different person by the end of the film.

To make is more simple, start them off as the best person in the world, but they don't like (blank). Through a series of meetings and mishaps, this person begins to (blank) in order to change their ways to become a better (or worse) person than when they began. This makes everything simple, yet can be made into a very complex string of instruments.

Now go back to that script you thought was good and make sure the main character changes throughout the course of the story. They should be two completely different people from the beginning of the story to the end.

Sincerely,
Future Film Guy