One way is to have a vast reservoir of ideas. For example, draw inspiration from different cultures, historical events, or personal experiences. Also, creating a set of recurring characters or a common fictional universe can help. You can start with a basic concept for the first novel and then keep expanding on it with each subsequent book.
To create an endless series of novels, you need to be highly organized. Keep track of your plotlines, character arcs, and any loose ends. Plan ahead for future installments. Additionally, engage with your readers. Their feedback can give you new ideas and directions for the series. And don't be afraid to experiment with different genres within the series to keep it fresh.
Firstly, you must develop a passion for writing that endures over time. A love for the craft will keep you motivated to continue the series. Next, build a strong foundation in writing skills like grammar, vocabulary, and storytelling techniques. Research is also crucial. Whether it's about a particular place, time period, or subject matter, thorough research enriches your novels. Continuously challenge yourself to come up with new and exciting storylines to keep the series going.