As far as a planning process goes for my storytelling, there really isn't one at all, to be dead nuts honest. What more or less happens is I start to get this really agitated feeling; it isn't a good or a bad it's a restlessness, like there's something really important on my mind but I can't for the life of me think what it might be. So I go about my business doing whatever it is I need to be doing, trying to not think about that itchy restlessness and then something happens; I read something in the papers or I overhear some conversation on the street or I have some oddball daydream and it's like the tumblers on a combination safe somewhere in my subconscious just click into place and the vault door swings open and inside are all these pieces of an idea; they've been there all along but for whatever reason they're not isolated fragments and broken pieces of unrelated ideas anymore, suddenly they have cohesion and connectivity so I start to put the pieces together. Idk if that's a helpful answer or not but that's how it works for me. I'm honestly glad I don't have to make a living as a creative artist; I have literally no idea when or where the muse strikes.
All that being said, the next steps past that initial inspiration burst depends on what just struck me. As I start to put flesh on the bone, so to speak, I do have these wonderful bags and boxes full of composition books dating back decades as sort of a tried-and-true reference work on myself, haha. These are all the little dialogues, scenes, sketches, vignettes etc. that I went on my rant about earlier. They're not particularly organized but I do keep coming back to several meta themes again and again which is very useful for focusing concepts- that's the beginning phase of development for me, trying to figure out what it is I want the reader to be thinking about when they have finished with my work. Structurally, my job from there is the building of the medium that will most effectively communicate the essence of that message. Whether the story eventually turns into an essay, novel, play, poem or song really depends on how much of that restlessness remains of what I felt before the lightning strike. The residual levels of that feeling dictates whether the end product is a hundred word drabble or the footers of a bridge arching to something much more. At the moment I seem to be really juiced about this historical fantasy I've been working on; it started out as nothing more than a tirade against government intervention in the 21st century educational system and within three weeks metamorphosed into an ongoing series of novels set in Edwardian England. Go figure 🙂