Some authors have a rigorous process for writing. I don’t; maybe that’s why my Pulitzer Prize is delayed.
The way I write sometimes is to ask, “What if?” I wrote a hundred thousand word book once based on the question, “What if Forest Gump had a normal IQ?” The narrator is reasonably bright, but no genius. He stumbles into things, like automating his college’s lawn watering so that he can work one hour and be paid for eight. His uncle’s website business depends on viewers paying to watch live action. He stumbles into automating notifications to viewers of upcoming shows.
He stumbles into creating a business for his college friends to sell services in their majors over the internet, which eventually becomes a billion-dollar company. He stumbles into a chance meeting with a governor, who is eventually elected Vice President, and the Vice President’s wife, a nurse-midwife, delivers the narrator’s first child. Forest Gump with a normal IQ. I’ve used this approach in two or three other tales.
Sometimes I have an idea, and write a few thousand words about it to see if it will work. Most don’t, and I’ve thrown away probably a dozen or more partially-written books. “Four Seconds on the Clock” started out that way, about a high school basketball team that wins its games not on talent, but by messing with the other team’s minds. Two characters took over, and when I done it was a story about two young men dealing with the aftermath of trauma. I’m still trying to write the intended book.
Occasionally I’ll have some specific scenes in mind, and write them out. From there, I connect the scenes and let the plot create itself. “Life Struggles” was written that way. And, occasionally, I’ll think through the entire book before writing the first word. Both “Taunting” and “The Trip to Helen Gawne” were completely thought out before getting started.
Thinking through the book completely appears to achieve the best results. Eventually, I’ll probably adopt that as my rigorous process.