Writing a first draft is like building a Roller coaster in realtime
This is just how I work... I'm not some academy award winning writer or anything... just sharing my workflow...
Create a bunch of notes about a particular set of ideas that could become a theme for a film... write them down in a text file or in a real notebook... write them all as fast as you can think of them... have fun and be crazy with the ideas... write them in no particular order... they can be scenes... character quirks... locations...anything... Spend a day or two doing this...
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Look over those notes... is there enough to make a film from? Is any theme or story idea grabbing you and nudging you to go further? If the answer is no, start making new notes based around a new film idea... If the answer is yes then move on...
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Now after studying your notes that have bits of characters, scenes, events...locations... write a short outline for a film based on those notes... make it very rough... your just laying out a very flexible rough form of what could be the story... it doesn't have to be detailed at all... now after writing it out across a page or two look it over... does it seem like it would be a good film? Is it visual enough? If not maybe its better as a book? Can you see the act breaks in it? Can you feel the suspense/comedy/action/horror or whatever your going for by glancing at this outline? If yes then move on... if not try rearranging the elements or changing some things in writing a new more compelling outline that would make a visually compelling film...
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Now at this point our procrastinating fearful self will want to "research" and "better prepare" for writing an actual first draft... but accept that your first draft is just the first step to a finished script and if its crap its ok it'll probably have tons of holes BUT your still going to WRITE... So grab Celtx or Adobe Story of Final Draft or whatever and write a script... don't even look at your outline or notes... just drop down that first slugline..
EXT. FOREST- NIGHT
A man with a crooked hat and a wry smile sits down in front of a small glowing laptop. Without any hesitation he begins pounding away on the dimly lit keyboard.
M DOT STRANGESo yeh then you just start writing... it should feel a little scary and chaotic likeyour on a roller coaster... and the roller coasters tracks are being builtin front of it as you speed along... actually YOU are BUILDING THE TRACKSWITH YOUR MIND! So don't worry about whether if it's going to crash or not justgo as fast as you can laying those tracks out... and make it an excitingride! Lots of twists and turns! Slow builds uphill then when you least expect itit speeds downhill at breakneck speed.
Once you finish the first draft THEN you can look it all over a million times and perfect each twist and turn... you can move pieces of track around... do anything you want to make it the way you think it should be... Go ride other roller coasters you enjoy... then come back to yours and compare it... What's missing? If you keep banging away you'll figure it out...
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Once you deem your roller coaster fit to be open to the public THEN you can storyboard it!
Brought to you by professional weirdo M dot Strange.