Okay, so discussing plot seems out of place in a series about pantsing, but trust me, it’s needed. Without it, you’ll get kudzu subplots (get me tired and ask me about the Epic with Everything one day), main characters who suddenly take a left turn to Neverland mid-book, or worse. As someone who’s managed to do practically everything you can do wrong plot-wise, all in the same book (with the exception of not actually having a plot), I have a good idea of what happens when the pants take you down the wrong trouser leg. And these are strange pants. They have an infinite number of trouser legs, some of them interconnecting, and not all of them will get you to the right ending (by which I mean the ending which feels like it’s the only way the book could have ended).
To stretch the pantser metaphor even further, your journey through the pants can have results you really don’t want to talk about.
So, how do you deal with this?
You study. You read well-plotted books (Terry Pratchett is a pantser, and his plotting is damn near flawless, especially in the later books), and good books about plotting. You also get to know the major plot structures and work out which ones apply to your vague notion of where you’re going. This builds up the ability to see the evolving plot as the pants permit, and make sure that external events keep your plot more or less on a viable leg of the pants.
The judgment of whether a clue-bat from left field is a good thing or a bad one is something that pantsers tend to learn by doing rather than from external sources. I find that if something belongs, once it hits me I literally can’t see the story working any other way. If I’m in doubt, chances are I’m wandering into a dangerous leg of the pants, one of the ones with the little signs that say “Here be dragons”.
Handling that judgment also means being willing to throw out a whole lot of wordage to get yourself back on a good leg.
My method – derived from my days scribbling in anything that came to hand and stealing time from everything I could – is to obsessively narrate the piece in my head, usually starting from where I currently am although I do get previews of later scenes. Each time I do this, it’s slightly different, and sometimes takes me into dangerous pants legs, but by the time I’ve sat down to write it I’ve got a fair idea what should be happening for that section.
In short, I micro-plot. I work out what should be happening in the scene I’m currently writing and maybe the scene after that, but no further. I still know the general shape of where I’m going and sometimes know what the basic plot type is (the current piece falls into a rather perverse hero’s journey, more or less. Possibly a subverted hero’s journey).
Looking for this kind of structure helps to deal with the kudzu subplots – which will otherwise infest and possibly strangle your story. If you can’t tell which of your characters is the protagonist, you’ve got this problem. Even cast-of-thousands novels have exactly one character who is the core of the piece. At least, if they’re written by someone capable of plotting, they do. Someone who can’t carry a plot in a bucket (not naming names here, but some quite prominent Names suffer from this) will have multiple character threads that don’t support each other and don’t focus around a single core.
I’ve found that there’s actually a sneaky way to work around this, and even better, so long as you’re not trapped in the damp crotch of the pants, it can happen at any point including after you’ve finished the draft.
First, ask yourself what the big problem that’s biting your characters actually is. This is important, because it might not be what it looks like on the surface, and you need to identify the big problem (this, incidentally, is probably pretty close to what your book is about – and you might not know what it is until you’ve got a fair way into the piece, because you’ve been busy working with the surface manifestations of the big problem).
Now, once you’ve got that, the next part is a bit easier. Who is the single person the problem bites hardest? It may not – read Snuff for a good example – be the person most hurt by it, but will often be the one person whose personal ethics are so utterly incompatible with the big problem they can’t do anything except try their hardest to kill the problem. It can also be the person who stands to lose most if the problem isn’t resolved. Found them? Good. That’s your protagonist.
With your big problem and your protagonist identified, you can prune any kudzu that doesn’t do anything to either move the story or shed light on your protagonist. Or you can tweak it so that it does do something in that direction.
What often happens with pantsers is that once you recognize the need for this and know what you need to do for it, the hooks are already there. They just need to be polished a bit and have the appropriate bit of window dressing hung on them. Occasionally, you’ll need to add in the big arrows pointing to the clue, and the flashing neon lights saying “Here! This is important!”
After you’ve been at this for a while, you’ll find that something you didn’t foresee fits perfectly with the odd bit you added in ten chapters back because it felt right even though you had no idea why it should be there. This, fellow pantsers, is a Good Thing. It’s a sign that you’ve internalized plot structure enough that your subconscious is guiding you through the pants in a way that won’t get you stranded anywhere.