The general story arc.
Use this arc to document your story–plot the points of your story on the arc, and you’ll see if it goes off the rails at all, and how to implement a bit of flow and proper story arc to your story in order to get it arcing in the right direction. Every story follows a natural arc–it begins, you introduce the characters, they find out about one another and develop feelings and define their own inner conflict that leads to external conflict. Then, Crisis! The black moment where it looks as though they’ll never get together, followed by a realization of what they want and who they are, a coming together, and then a resolution of the situation leading to the Happily Ever After (HEA).
*Note* This is one example. There are tons out there, some with a sharp, short start to the arc and a longer resolution period, and some with a long build-up and a short, sharp resolution period. The point of them is to make notes on this type of arc to see where your story is: where do YOU introduce your characters? Where is YOUR black moment? Does the first sex scene happen before the first kiss? If it does, is that a problem/does it make sense? Do you start resolving the problem before the black moment has even happened? If you do, can you do something to change that, and make the black moment that much stronger by not already starting the resolution beforehand, thus making it even blacker? If you make simple notes along this type of arc, you’ll see where you may need to move some chapters around, insert extra scenes, etc.
Yet another useful arc template is the character arc.
This one tracks the changes a character goes through throughout the course of the story. Who are they in the beginning? How does the reader get to see them change? At what point do they have their pivotal moment, the one that makes them decide to plow forward (or turn back)? Does it happen in the right place?
They start one way and end up another. This doesn’t have to be some huge change–they can just learn something about themselves, or learn to think differently about something particular. They can sense they have feelings for someone, particularly in a series where those feelings could develop in another book.
But they MUST change in some way. A character that is exactly the same from first moment to last is static and boring. Dynamic characters shift with the story, and by the time the story is resolved, so too should the character have some kind of personal revelation/resolution as well.
And you don’t want them changing at odds with your story. Some big self-understanding that happens before your black moment doesn’t work–it’s the black moment that drives the characters growth. And you don’t want to struggle forever to get the character growth–if your story is done, your character should be about there as well. You don’t want another fifty pages of character growth when the story has long finished.
The key here is to go through your manuscript and see where it happens–not just assume that it’s happening in the right place. The concept of your character that you have in your head–is it on the page? Doing a character arc can help you see if your character has understood everything/changed too soon, and therefore the reader may disengage because the character (and their struggle to overcome) is no longer interesting.
The Action–>Reaction arc (weaving it all together):
When you’re building a story, you have (at least) two layers:
You’ve got a story arc, with a beginning, middle and end, and a logical progression through each step.
And you’ve also got a character arc, where you meet the character and see how the story changes them as they go along.
There is an element of Action–>Reaction involved here. Something in the plot happens, and the character should react in some way. That reaction can often be the catalyst to drive the story forward (and back into Action). When you plot the arc, if you’re seeing plenty of Action (story things happening) but your character isn’t doing a whole lot of reacting to these pivotal moments, then you’ve got some work to do. Slow down. Make them think. Make them feel. See how your plot points correlate to your character’s personal journey and weave them together.