One thing that has always impressed me with good writers is their ability to break scenes down in their movies when being interviewed about them afterwards. They are articulate and know how to explain each scene or moment with some amount of depth. I noticed also how many start-up writers tend to think this all happens in hindsight, but what I think they don't realise is that many good writers actually employ the methods below I go into of creating beats for their work, even if they don't write it down formally. Writers tend to be doing this constantly in their mind or verbally through discussion.
That's why I think it is essential for start-up writers to use formal treatment processes if they haven't developed the habitual knack for it mentally. Sometimes I'll ask a writer why they put this or that into a film, and the response is "I don't know, I just thought that's what they would do in that situation", or "I just thought it was better that way", regardless, that might be all well and grand if your using the response to come across all intuitive or "anti-intellectual" - but having some layers to an explanation is not being "intellectual", it shows commitment to the creativity, and allows us to either think what your on about is bollocks or provide some further depth to what we see.
To aid you in the process of mapping out your Treatment you may wish to employ a One Liner Scene List (Also called a Beat Sheet or Step Outline) so that you cover the whole Treatment in its entirety including back stories, or character developments along the way. A One Liner Scene List is like blocking a stage play, in a stage play during rehearsal it is essential to mark out what is happening at all times on the stage, working out where the action is going to take place and why the characters are doing what they are doing at each moment of the narrative; this can only be done by reading into the meanings behind each scene. Motive moves the action and dialogue along the continuum of the narrative's plot. Motive is just as essential as conflict in stimulating the audience.
In a Beat Sheet you will write down "What happens" and follow that up with what the scene is about, so "Why it is happening".
In this sense you can block the narrative from node to node, and I use the word node as a narrative convention based on the process of determining the structural stability of our narrative via a time scale. The narrative which involves me doing the dishes and stating that I will be doing the dishes soon, has a distinctive two nodes of motive, one of which I state that I will be doing the dishes and the other in which I actually do the dishes. There is time represented here which is anticipatory and two important occurrences take effect, my expression of doing the washing up and my foreseeable action of doing the washing up. Two beats.
This Temporal space needs to be structured to show a progression of time. From when we as the viewer first are aware of the motive to when the action actually takes place. Whether you call them BEATS, BLOCKS or STEPS is up to you but an example might be ... using a classic scene from Monty Python's Holy Grail.
ARTHUR: Old woman!(Sourced from: Georg Rehm's Monty Python archive)
ARTHUR: Man, sorry. What knight lives in that castle over there?
DENNIS: I'm thirty seven.
DENNIS: I'm thirty seven -- I'm not old!
ARTHUR: Well, I can't just call you `Man'.
DENNIS: Well, you could say `Dennis'.
ARTHUR: Well, I didn't know you were called `Dennis.'
DENNIS: Well, you didn't bother to find out, did you?
ARTHUR: I did say sorry about the `old woman,' but from the
behind you looked--
DENNIS: What I object to is you automatically treat me like an
ARTHUR: Well, I AM king...
DENNIS: Oh king, eh, very nice. An' how'd you get that, eh? By
exploitin' the workers -- by 'angin' on to outdated imperialist
dogma which perpetuates the economic an' social differences in our
society! If there's ever going to be any progress--
Beat 1: King Arthur is seeking to find out what lies within a Castle, he mistakes peasant man as a woman. Playing on the idiom of "They all look the same", this is called "othering", things of the unknown known only in the minds of those who wish to describe them, the King treats the peasant as an inferior which was common with class-systems, this is what we may refer to as a Binary Opposite.
Beat 2: King Arthur further mistakes the man for being old when the man is only 37. Titles of nobility assuming an "ageist" remark instead of a courtesy title commonly used by the aristocracy, this is opposed to an egalitarianism approach which would be to ask politely for the character's name.
Beat 3. Dennis picks up that he is being treated as an inferior, King Arthur confirms this by stating that he is King. Discourse on the hierarchy of medieval feudalism.
Of course I have chosen to break this scene down virtually line by line, however in my Beat Sheet the scene may lend to less examination on the "whys" and "whats". Possibly the more important the scene the more you may need to isolate the steps.
The is important for work conducted by crew such as the Cinematographer, in the Monty Python scene, the King is always on higher ground, he therefore codifies a higher authority simply in the framing of the mis-en-scene.
If I were to block this entire scene I might present it like this ...
Beat 1: King Arthur approaches peasant asking about Castle as he is in search of the Holy Grail. Dialogue on the inequality and delusions of grandeur held true by autocratic sovereignty presented by a farcical feudal dichotomy when a King and lower-class peasant with an "ascribed status" meet. King Arthur as autocrat has his divine right metaphorically and almost literally slung with mud.
Now, this is a pretty easy scene to break down into beats, because the beats are virtually written into the scene anyway, which means I don't have to second guess the what and why of the scene, but with more subtle dramas and narratives, or concept films, it's a key to keeping the idea flow parelel to the production workflow.