Some storytellers are so captivating that we don’t see the flaws in the story until we have a “refrigerator realization”, where you’re standing in front of the refrigerator and realize that there was a gaping plot hole. Usually, you don’t care, because you were entertained. For most of us writers, though, it’s important that each character have their own arc, and that there be arcs within these arcs if the work is novel-length.
One of the most popular methods of doing this is the so-called “snowflake method”, in which the basic plot is decided first and then each area of it is complicated with further subplots. I prefer to plot a bit differently, though. For me, the primary interest is not so much what happens to the characters (though I do write that, of course) but who the characters either become or are revealed to be.
Not every character needs to change so long as our perception of them changes. In mysteries, for example, we don’t read to see the killer become remorseful, we read to find out more about a world we see only incompletely. For me, writing in this way means that I am not so much taking my characters through things as I am shifting a window that lets us look at them. Some parts will never be seen clearly, and other parts will be very clear. The overall arc is how we view the character, and the subplots and mini arcs are the snapshots we get of this character, from which we construct our own view.
How do you organize your stories at the broader and narrower levels?