All great suggestions. Finish the first one before you do anything! In working with directors and production studios, the script often changes in process of going from spec to shooting. So keeping it tight is a big plus. When you're shooting it yourself, you can get away with being a bit verbose. But if your goal is to sell/option it, keeping it to 90-110 is ideal depending on the story.
To help guide you in your revision, there are three areas to watch for:
1. verbose action/description lines
2. dialogue
3. scenes that are cute but not essential to the story
These are in order of easiest to fix. Below are guides and suggestions, not rules!
1. Keep action and descriptions to a minimum in the script; 1-3 lines is ideal.
Code:
Example:
EXT. CABIN IN MONTANA - DAY
JOE, a young college kid with windblown blond hair in cutoff
jeans, is looking out from the peak and surveying the pine
ridged mountain peaks surrounded by marshmallow clouds.
The sun is shining down and casting a moving panorama of
shadows from the high clouds overhead.
[COLOR="Blue"]Nice for the creative writing class, bad for a screenplay.[/COLOR]
EXT. CABIN IN MONTANA - DAY
JOE (20s) stands on a cliff edge in shorts and surveys the
pine ridged mountain peaks. Shadows, cast by clouds, move
about him.
Remember that a lot of creative people will take the script and re-interpret it for costuming, location, etc. If it's not integral to the story, weigh how important the detail is. How do you show someone he's a college student? If it's imperative, you could put him in college apparel. The actor may end up being brunette. I also made sure to make the verbs active rather than progressive ("am/is/are X-ing").
2. Dialogue is more tricky. It's important to understand that how we talk normally is HIGHLY repetitive. By observation, scientists have found that nearly 70% or so of what is said is filler. This seems to have an inflation effect on screen. So avoid saying what can be shown or is seen happening. Don't use dialogue to explain your story! Especially relying on lots of voiceover or narration. Don't spend more than two lines on everyday small talk. Get to the meat quickly. And avoid having characters repeat what the audience has seen. [NB: I'm not using proper format here to conserve space.]
Code:
Example:
JEAN: Oh hi, Phil. How are you today?
PHIL: I'm good. And you?
JEAN: Can't complain.
Jean's dog takes a dump on the neighbor's lawn.
PHIL: Oops, looks like Mr. Whiskers just took a dump.
JEAN: Yeah. And I forgot my doggie bags. ... Again!
PHIL: You heard about someone breaking in to Martin's house.
JEAN: Are you serious? When did it happen?
PHIL: Thursday night around 7:30 pm, I heard.
JEAN: Anyone hurt?
PHIL: No. Everyone was at Bingo at St. John's. You know,
the Catholic church behind the grocery story on 3rd.
JEAN: Oh, yeah. I know that one. Anything valuable taken?
...
[COLOR="blue"]Very nice and chatty, but not for a script where space = screen time[/COLOR]
Rather:
JEAN: Oh hi, Phil. How are you today?
PHIL: I'm good.
Jean's dog takes a dump on the neighbor's lawn.
JEAN: And I forgot Mr. Whisker's doggie bags. ... Again!
PHIL: You heard about someone breaking in to Martin's house
Thursday night?
JEAN: Anyone hurt?
PHIL: Steve said they stole cash and electronics while they
were out playing bingo at St. John's.
...
As a general rule, don't use "yes" or "no" in dialogue. For important story points, I piggybacked them on other dialogue. If this is a mystery, St. John's might be important if not previously introduced. Here I included it. The audience really could care less about where St. John's is located. Be selective about what is told. With a light juggling, we reduced eleven lines to six.
3. Removing scenes. Here's where it gets painful. We all have our favorite scenes/dialogue. It hurts to cut them out. Some scenes add depth to the characters but aren't integral to the story. One trick that can sometimes help, after you've done the above two steps, is to make a copy of your file. Now delete ALL of the dialogue. You are just left with the visual description of your story. It should tell the story. If you read a scene that now seems out of place, remove it in this duplicate. You're honing the visual story now. Make yet another copy of your original and delete the corresponding scenes. If you're using a software program that numbers your scenes (ordinarily you don't use that in a spec but it's helpful for revisions), you can immediately cut the proper scenes. HOWEVER, if you're using CeltX, work backwards from the end. CeltX renumbers scenes dynamically if you work from the front, you'll change all the numbers that follow leading to some rather unpleasant editing surprises if you're not careful!
Having done the deletions, you now need to go back and do "plot damage control". Make sure that the removal doesn't ripple forward or backward.
After going through these three steps, you now have to re-evaluate your script. Is there a better, easier, more clever way of getting from point A to B? This is not a total re-write but may require significant changes. As such, I always number my drafts so I can refer back to earlier versions--SCRIPT_DD_RR where DD= draft number and RR=revision number. For me, a draft is a significant change in material. A revision is a version with minor corrections (spelling, grammar, etc.). I haven't had any script draft break into the double digits yet. Maybe if you add in revisions.
Hopefully these hints will help you go back through your script and identify ways to pare it back in your rewriting/revising. Good luck!