Not sure if I can help, as I am only good with writing fan fiction novels or stories for others >.>
But, I always start with the idea I have in my mind and from that point on work further, as an example: Characters > Bio > Location > Event > Script > Wing it > The End.
So it usually comes out like this (as a in the middle part):
''Miranda, suddenly stood still in the middle of the streets, looking around her and seeing not a single living person wherever her eyes were looking towards... and with a deep sigh she said to herself''
Miranda: Sigh... Maybe I am cursed to be forever alone.. If only my family did not-
And that's about it. I often create fan fiction/stories in this kind of way (not story wise xD). But, I do always keep on re-reading/editing, with every single sentence I add, in order to check if it works.
If it is for something, as in multiple chapters (Long Run), I tend to write the first chapter in the form of a long essay and the further I go before finalizing I keep adding more and more thumbnails for the next one in order to keep track on the progress and continuation of the plot.
Not sure If I was helpful, sorry!