Future Story Ideas
As a writer, it is good to keep a log or a small book that you can write future story ideas in. Something that you can keep handy when you need to start a new book.
Writing Prompts
Writing prompts are great. I particularly like the ones that give you three or so words and you must write a short story or vignette with them.
Reflections on Writing - Plan
You have to have a plan. It is more important to know the ending than to know the beginning. The beginning can always be adapted, modified or changed. But the ending is where you are heading.