This is probably the easiest way to write a book.

1. Go to TV Tropes.
2. Click the random trope button. Don't look at the bottom of the page. The random trope button has some dice and “Trope” on it. Keep going until you get a good one, then right click and click “Open in New Tab” instead of just clicking.
3. Record everything that comes up. Leave the tabs open, but close contradictory ones or those that you don't think fit the others. (Optional: When you have enough, click Media to write a fanfiction!)
4. Write a story base based on the tropes.
5. Expand on it. Create the plot.
6. Create the characters and the universe.

i believe that's how frank r. stockton came up with most of his stories!