I am learning that stories tend to have a regular pattern and the reason for this is that they reflect the way we think. We have a thesis and we challenge the thesis with its opposite then we synthesise or integrate the result into our mind/heart. You could have a character who has traits and they then meet their opposite. They must become involved somehow with this person and eventually they come to terms with what this person brings and the original character changes. So the main character or the one whose POV we are looking at, they may have one fundamental flaw or fear, this may be challenged by this opposite person and the main character must face their fear by accepting, reluctantly the call to adventure, they arrive at the end of the story changed and bring the knowledge back to home.