My piece-by-piece scenes rarely work, but that's okay, and planning might help
I write fiction a sentence at a time, one each day. That's my routine minimum. On a good day, I write an entire paragraph or three.
I'm pretty happy with how the prose comes out this way, but less happy with the story. There's one quirk: I often write scenes without any clear intention—and often entire stories.
The unintentional scenes tend to look like superficial mashups of half-remembered scenes from things I've read and watched. They fit with the other parts of the story in vibe, but come with quirks. They tend not to fit clearly with whatever I might have thought I was trying to do with the story. They often lack a clear reason to be written out in detail. They tend to lack strong conflict, instead having weak environmental conflict ("I don't know where the thing is—I looked for it in a few places—oh, look, it's over here") not satisfyingly resolved, a weak interpersonal conflict with escalations not foreshadowed, not surprising, and not costly to the protagonist, or no conflict at all (simple conversation).
I have a suspicion that more completely outlining my stories would help. I have never written a story from a complete start-to-finish scene outline. The way I write sentence-by-sentence means that inevitably some days I sit down and have to start a fresh scene without a plan. So, I'll toss out a sentence or three that sound all right and call it a day—there you have it, beginning of scene, go from there. When I'm feeling kind to my future self, sometimes I'll leave a partial sentence or a clear hook for the next thing to write about. This need not be consistent with the direction implied by the previous next thing to write about.
For no particular reason, I don't plan these new scenes out before I write them—not even just-in-time. I wonder if it would be a good idea to start each unplanned scene by sketching some a plan for what the scene could be—some high-level ideas and then specifics about conflict and theme and character. That might help.
But thinking back on it, I wonder if I need to.
I wrote an unintentional scene recently that amounts to "protagonist looks through someone else's cardboard boxes, then finds a clue while leaving the room." It's followed by another (in progress) that may summarize to "protagonist use computer." These are exactly the kinds of scenes I worry about.
I tend to be harsh on these scenes, maybe more than they deserve. Looking back on the box scene, I can see there are things here that fit in with the theme and the things I'm doing with the story. The computer scene, too. I may only need to draw those connections out more. There isn't much conflict, sure, but that might be okay. They're only a few hundred words. If anything, what is maybe lacking is a sense of what I'm doing with the protagonist. I had a vague notion at one point but it seems to have slipped my mind.
It is a first draft. These aren't terrible mistakes. I can fix them in editing. The worst case is that I have to toss the scenes and replace them. It's workable.
But I hate replacing scenes. I'd rather get the scenes right the first time so I don't have to replace them.
There's something frustrating about replacing a half-functional scene. I have to fit it in with what comes before and with what follows, which means I've got to know what I established in the scene I'm replacing, which means I've got to read it closely. But that's the last thing I want to do when I "know" the scene doesn't work. I feel bad for having written a scene so lacking in the basic elements of what a scene needs. It reminds me that good construction isn't automatic for me, that I can't just write and expect a coherent scene.
I feel like I ought to be able to write like that. I don't enjoy writing outlines, but I do sometimes (!) enjoy dashing off a scene. That's a process I like, "my" process. Shouldn't it work out for me?
Maybe not.
Do I enjoy writing outlines, actually? Not as lists of one thing and then another, but I have enjoyed sketching ideas for things that I could write into a story. Those ideas don't necessarily connect. It's the filling-things-out that gets tricky. There's a sense that it ought not be done mechanically, insisting on doing it by feel, while not having a strong feel for how the outline 'should be' filled out. I think what worries me is the thought that I could just as easily write in pointless scenes in an outline. I wouldn't have any excuse for writing down that pointless scene in the outline, let alone writing it.
Maybe that's part of why I don't outline: If I plan the structure in advance, I have no excuse when the structure doesn't work. I can't say, "I didn't plan it in advance." I have to say: "I planned it but my plan didn't make sense."
Maybe I should try planning badly. Just-in-time planning of scene, character, conflict, and theme might help. And maybe I should try reading closely those "bad scenes." I'm harsh on them, but I know I've read worse. Listing out what they do might make replacing them easier. It's certainly workable to fix up everything around the replaced scene. After all, I have only been writing short stories lately.