Basically, I was looking through my old Reddit posts, and this was just something I left in a post about how to get started writing a screenplay. I actually think I gave pretty solid advice, so here it is:
First off- you have to already have the idea. Don’t try and sit down at your computer, ready to write, if you don’t have an idea yet.
If you struggle to come up with ideas, speak to friends about hypothetical movies- even if they sound REALLY silly. Take an idea and just run with it, just as a general exercise.
A lot of my ideas come from personal frustration that I really want to see a new movie in a certain style, that nobody is making any more. Usually something I grew up with. Then I run with that idea and start thinking of what I’d like to see done in that style. Chances are, the final product won’t at all resemble it, because the story just ends up going a different way – and it becomes its own animal.
Once you have an idea- start to refine it based on practicality. What is it for? Is this a script that you want to sell to a large production company, or is it an independent film you want to put together yourself?
Think about what you have access to, and base what you write around your limitations. Even if you plan for it to be a big budgeted blockbuster – think as small as you can. Simplicity is key- and you don’t want to write loads, only for the company to start tearing out pages because they can’t afford to film those scenes – or for what you had planned to look like crap because it’s beyond the company’s or your own personal means.
The three act structure is your friend!
Write out simply what you want to happen in the beginning the middle and the end, as bullet-points.
Then split each of those stages into three more. Then you split THOSE stages into three more.
Once you have that – you’re ready to start writing.
Try to focus on one or two main characters. Ensemble pieces can be great – but can you guarantee that you’d have access to enough strong actors to pull it off? Also, when you’re starting out, focussing on one or two characters can really help you learn to build strong characters, because you’re not constantly switching your focus and bloating your story.
The only other thing I can say is to play to your own strengths. If dialogue is something you’re good with, then centre your script around interesting conversations. If you have a very poetic brain, and have a knack for symbolism and layers of subtext- then maybe don’t aim to make the next Rambo movie.
If action scenes are your bag- keep in mind your limitations, but still play on it. Look at a movie like The Warriors. Plenty of action, but it’s mostly street fights and brawling. Simple to choreograph, easy for actors to learn, and no need for big special effects.
Lastly, don’t worry too much if what you write isn’t always very good. I scrap more screenplays than I keep. That’s just a part of the creative process.