The following is adapted from the book "Save the Cat" and is intended for full feature-length scripts (generally 110 pages-- page numbers by each beat are approximate). If you are writing a short film, the same beats apply-- they will just be shorter and more condensed. In fact, here's a completed beat sheet to Pixar's short film "Lava" that played before Inside Out.
BLAKE SNYDER'S BEAT SHEET
1. OPENING IMAGE (pg. 1)
This is the first impression of what the movie is going to be. Should establish mood, and type of film.
2. THEME STATED
Somewhere in the beginning of the screenplay, a character (usually not the main character) will say something or pose a question that will serve as the theme of the film. Sometimes it’s a little sneaky, but usually always there— you just have to be listening for it.
3. THE SET-UP (pg. 1-10)
Set-up the world of the screenplay. Introduce the main character and most supporting characters. Establish the location, time period, etc.
4. THE CATALYST (pg. 12)
The catalyst (or “inciting incident”) is the moment where something happens to kickstart the main story— like getting fired from a job, getting news that you have 3 days to live, discovering that your parents are getting a divorce, being evicted from your apartment, etc.
5. DEBATE (pg. 12-25)
This is the section after the catalyst when the hero (main character) must decide if he will “go for it” — whatever opportunity or danger has been posed by the catalyst. The hero should be asking him self “Should I go?” “Dare I go?” “What are my other choices?”. The debate section must ask a question of some kind. In the movie Legally Blonde, the catalyst is when Elle Woods’ fiancé dumps her— the solution is that Elle should follow him to Harvard Law school, the debate: “But how will she get in?”.
6. BREAK INTO TWO (pg. 25)
This ends the debate section with the hero finally making the decision to go for it— to leave the old world behind and proceed into a world that is different. With this decision, we break into the 2nd Act of the screenplay (total of 3 acts).
7. B STORY (pg. 30)
For many screenplays, this is the “love story”. But it can also be a friendship, or special relationship. This story carries the theme of the movie and usually introduces a new character— the “B-story character”— or set of characters.
8. FUN & GAMES (pg. 30-35)
Fun & Games section usually answers the question: Why did I come to see this movie? What about this premise is cool or funny or action-packed? Often, most of the clips used in the movie trailer come from this section.
9. THE MIDPOINT (pg. 55)
The midpoint should be about halfway through the movie. It’s either an “up” (hero peaks, things are really good) or a “down” (world collapses around the hero). The “stakes” (“stakes” mean what would happen if the hero should fail— will the world be destroyed (high stakes) or will the hero just not get that job they wanted (low stakes)) are always raised at the midpoint. If the midpoint is an “up” it’s a false peak— things are about to crash down. Or if it’s a “down” it is also false— things are about to get better.
10. BAD GUYS CLOSE IN (pg. 55-75)
Good-bye fun and games. We are thrust back into the conflict of the story. It’s the point when the bad guys regroup and send in the heavy artillery. It’s the point when characters in the hero’s team begin to turn on each other.
11. ALL IS LOST (pg. 75)
The opposite of the midpoint. If the midpoint is an “up”, then the All is Lost moment is a “down”. Often labeled the “false defeat” when all seems to be lost.
12. DARK NIGHT OF THE SOUL (pg. 75-85)
“The darkness before the dawn”. The moment when the hero is the lowest of the low. How he feels at the All is Lost point. It is the moment before the hero reaches down deep and discovers the solution that will save himself and everyone around him.
13. BREAK INTO THREE (pg. 85)
Hooray! The Solution! As we break into the 3rd Act, both the issue in the main story (A story) and the B-story is resolved by the hero. The hero has won, found the solution, passed the test, saved himself, etc.
14. FINALE (pg. 85-110)
The wrap-up. The lessons learned are applied. A story and B story end in triumph for our hero. It’s the turning over of the old world and the creation of a new one. The bad guys are dispatched. All is good again.
15. FINAL IMAGE (pg. 110)
The final image of the movie should be somehow opposite or related to the opening image. It is proof that a change has occurred and gives the film a satisfying “book-end” ending.
Use this method to plan out the structure of your screenplay. Next time you watch a movie, try to notice the different beats that make up the film. To read examples of beat sheets for real movies, Save the Cat's website has many examples.