1. Develop a strong premise: A strong premise is essential to a good horror and mystery novel. The premise should be something that is unique, intriguing, and capable of keeping the reader engaged throughout the story.
2. Create compelling characters: Your characters are the driving force behind your story. Make sure that you create characters that are relatable, complex, and interesting. Your readers should be invested in your characters and care about what happens to them.
3. Build tension: Tension is essential to any horror and mystery novel. You need to create an atmosphere of dread and suspense that keeps your readers on edge. Build tension slowly and gradually throughout the novel, until the tension reaches a climax.
4. Use sensory detail: Sensory detail is essential to creating a vivid and immersive world. Use descriptive language to create a sense of place and to engage the reader's senses. This will help to make the story more memorable and engaging.
5. Keep the mystery going: In a mystery novel, it's important to keep the mystery going until the very end. Keep your readers guessing and make sure that the solution to the mystery is not obvious. This will keep your readers engaged and interested in the story.
6. Use foreshadowing: Foreshadowing is a technique that can be used to create a sense of anticipation. Use subtle hints and clues throughout the story to hint at what's to come. This will keep your readers engaged and guessing about what will happen next.
7. Be original: Horror and mystery are two genres that have been around for a long time. To make your novel stand out, you need to be original and come up with something that is unique and fresh. Try to avoid clichés and predictable plot twists.
8. Edit and revise: Finally, make sure that you edit and revise your novel thoroughly. This will help you to catch any errors or inconsistencies in the story and make sure that everything makes sense. A well-edited and polished novel will be much more engaging to readers.