"In many cases when a reader puts a story aside because it 'got boring', the boredom arose because the writer grew enchanted with his powers of description and lost sight of his priority, which is to keep the ball rolling." ~Stephen King
It’s important to have enough movement in a plot. An easy way to do this is to include the correct number of action scenes (aka, scenes) in novels.
Scenes are generally 1200-1500 words long. (Books have approximately 70% scenes and 30% sequels.)
A scene can be divided into three parts:
The action scene is where the viewpoint character tries to achieve a short-term goal. The character believes each scene's goal will help them reach, or come closer to reaching, their overall goal.
Every action scene needs to involve at least one other character who has a reason to oppose the viewpoint character. (There, of course, can also be additional characters.)
Example:
Overall Story Goal: Jim wants to leave his wife and start a new life.
Scene Goal: Jim needs to get to the airport to stop his visiting lover from going back home.
In trying to reach a scene goal, the viewpoint character must meet resistance, which leads to conflict.
This resistance could include:
Delay, malfunction, anomalies, bad weather, altercation, argument, seduction, chase, lying, waiting, searching, fleeing, manipulation, demanding, etc. There are lots of options!
Example:
Scene Conflict: Jim must pick up and drive his teenage daughter home first. When he picks her up, she’s late. They have an argument, and after, his daughter then tells him why she was late.
A character must experience failure in one of the following ways:
A failure must seem like a natural consequence of a character’s efforts.
Avoid failures being coincidental, for example, someone arguing with a neighbor shouldn't lose a disagreement because a storm arrives and forces them inside.
Example:
Scene Failure: Jim fails to get to the airport on time and his daughter has told him about her life-threatening illness. (Option 2 of the failures)
Tip: Most action scenes are followed by another action scene. Only if an action scene has a devastating result should it move to a reaction scene/sequel.