Tweaking: sorting out small details in the narrative, making sure all elements of the plot agree. The process might seem simple, yet I’m finding this stage of the writing the most difficult.
Possibly, the structural or plot issues have always existed in the story but have only come to light as the writing has got better. A bit like using photo editing software to improve a photo, only to find insignificant details suddenly detracting from the main purpose of the photo (as a result of the editing, of course).
Introducing complexity in order to solve a fundamental problem in the writing might solve the initial issue but will often bring about new problems in the narrative.
What’s complexity? I would define it as creating a new plot to improve or justify an old plot. The two plots co-exist in the same story. The new plot almost competes with the old, making the structure off-balance (my opinion, anyway).
So it’s back to the computer screen and more tweaking practice.