Prepare a synopsis or scenario of events in the order of their absolute occurrence—not the order of their narrations.
This is a practice adhered to by writers from J.K. Rowling and William Faulkner to Norman Mailer. It seems a an excellent general piece of advice for any kind of fiction.
Prepare a second synopsis or scenario of events—this one in order of narration (not actual occurrence), with ample fullness and detail, and with notes as to changing perspective, stresses, and climax.
Write out the story—rapidly, fluently, and not too critically—following the second or narrative-order synopsis. Change incidents and plot whenever the developing process seems to suggest such change, never being bound by any previous design.
It may be that the second rule is made just to be broken, but it provides the weird fiction practitioner with a beginning. The third stage here brings us back to a process every writer on writing, such as Stephen King, will highlight as key—free, unfettered drafting, followed by…
Revise the entire text, paying attention to vocabulary, syntax, rhythm of prose, proportioning of parts, niceties of tone, grace and convincingness of transitions…
Prepare a neatly typed copy—not hesitating to add final revisory touches where they seem in order.