I know not what path others may take, but as for me, it's the same path, over and over. As I write, I leave big holes, but as I edit, again and again, they fill themselves in almost as a matter of course. As big problems are solved, smaller ones come to light and get their turn for my full attention. It's the fourth time through that I see a tiny event that deepens the bad girl's motivation and makes her more realistic. On the sixth time it might be an incident that, added to the main plot, diverts the reader and allows for a bigger surprise at the end. And it's the tenth time through that the phrasing smooths out, making each character sound like himself, different from all the others.
It's how I work, and it's how I know I'm no Mozart, just a writer who has to work really hard to get better.