Re-read each scene in turn, seeking out:
1. Dialogue that can be replaced with visuals (or sound)
Can that line of beautiful, witty, moving dialogue be better expressed in a cinematic way?
Often a thought, mood or idea can be more strongly evoked by an action, a look, an off-screen sound effect or some similar piece of cinematic storytelling.
Instead of someone saying how angry they are, for example, we can see them crumple up a letter or hear them hammering a nail into a piece of wood.
2. Descriptions that are in the wrong place
Writers who've read a number of stage plays might be tempted to use the theatrical convention where scenes open with detailed descriptions of the stage layout.
However a screenplay must only give what's dramatically relevant at the time.
Don't start a scene with a lengthy description of the location.
Set the scene with a single pithy sentence and then move straight into action.
INT. LECTURE THEATRE - DAY
In the vast hall, long lines of chairs wait, empty. MARK checks the time on his watch...
If a prop, such as a lectern, is going to be needed later - then you can safely leave it out until it's needed.
3. Novelising
By contrast, novels and short-stories tend to describe scenes in great detail throughout. This too doesn't work for a script.
You may want to describe the bustle of the railway station, with those interesting odd-ball passengers, the ramshackle coffee stall, the sun slanting through the glass roof... But if it's not dramatically relevant you absolutely must cut it out.
Screenwriting is closer to haiku - a single well-chosen detail stands for the whole.
4. Mind-reading
At the same time, you can only describe what could be filmed (or recorded on sound).
So cut out all lines which tell us what someone is thinking, or remembering, unless the audience could reasonably work it out for themselves.
Lines such as
He stares out of the window remembering that this is the view that his ageing aunt would have seen just three days before she was arrested....
5. Editorialising
Similarly, you can't make editorial comments such as
Politics are a nasty business.
Instead, see if you can find an inventive cinematic way to make it clear what one or more of the characters are thinking. For all his dialogue skills, Aaron Sorkin is also brilliant at finding visual ways of conveying characters' thoughts.
6. The bleeding obvious
Delete anything that would be obvious from the context. If it's raining, you don't need to say that people are sporting coats and umbrellas. If the scene is a courtroom, we can assume there are seats, lawyers, a judge...
For the same reason, you shouldn't ever say that your protagonist is beautiful or fit. When did you ever see a movie where the star actors weren't!
Only include such things if they go against expectation - your hero doesn't have an umbrella in the rain, the hero is a fat slob, etc.
7. Locations that don't deliver
Many writers choose the first locations that come to mind and stick with them. But those first thoughts are rarely very exciting.
Look at each setting and ask yourself if it's adding the most it can to your scene.
Does that action have to take place in an office, or living room, or restaurant?
What about somewhere more unusual and evocative? Such as a graveyard, or the avionics bay of a jumbo jet, or in the middle of a martial arts class?
8. Descriptions that don't evoke
Finally none of your descriptions should be flat, dull or cliched. Good screenplays bring a moment to life in a short, freshly-minted phrase.
For the same reason, ditch technical directions such as camera shots. These should be avoided because they break the mood.
Use your originality and your language skills to the full to evoke character, location, atmosphere, action so that we get the feeling - from high tension to romantic bliss.
But keep it brief.
In the next episode...
By now your script should be really tight. Story, structure, characters, scenes, dialogue and descriptions the best you can make them.
There's just one big thing that needs to be done before you get it ready to send out. Indeed, the next draft could turn out to be the most important of all.
And that's the subject for next time.
Charles Harris is an international award-winning writer-director. His book Complete Screenwriting Course reached the Top Two this month in Amazon's bestseller list for TV scriptwriting and has been in the Top Nine for cinema scriptwriting for many months now.