You are an idea factory, turning raw materials into finished books through the power of your mind and hands. In order to successfully create, it's important to keep every aspect of this process functioning smoothly.
Every factory, and every writer, needs raw materials to work with. These raw materials are inputs to the creative process, and without them everything eventually slows to a complete stop. Your raw materials might include communing with nature, going to concerts and art museums and movies, reading, spending time with new people and visiting new places.
Transforming raw materials into finished products is a process of trial and error that eventually results in high levels of expertise. Be willing to continually reexamine both your methods and your results, and stay the course even when there is no immediate payoff.
Keep your idea factory full, with projects in various stages of development, so that when you finish one book you are ready to start the next. Capture ideas, review them regularly, experiment with them and don't be afraid to scrap the ones that aren't working. Over time, your idea factory will allow you to create a very satisfying body of work.