A plot twist is not something that you can just throw in at the last minute, but rather something that you need to plan, test, and refine. You need to make sure that your twist is logical, consistent, and coherent, and that it does not create plot holes, inconsistencies, or contradictions. You also need to make sure that your twist is impactful, meaningful, and satisfying, and that it does not disappoint, confuse, or annoy the audience. You can test your twist by asking yourself questions, such as: Does it fit the genre? Does it follow the clues and hints? Does it add value to the story? Does it subvert and challenge the audience? Does it surprise and satisfy the audience? You can also test your twist by getting feedback from others, such as: Do they see it coming? Do they understand it? Do they like it? Do they have any questions or criticisms? You can then refine your twist by making adjustments, revisions, or improvements, based on your own judgment and the feedback you receive.
Plot twists are a powerful tool for filmmakers to create engaging stories, but they also require careful planning, execution, and evaluation. By following these tips and examples, you can use plot twists to surprise, intrigue, and challenge your audience, and to make your story more memorable, unpredictable, and engaging.