Alright, sometimes just churning stuff out is not the way to go. Particularly, if you are not good at the word selection – you will end up spending a significantly longer time editing (rewriting) and that could kill off the creative juices.
It is always useful to have a vague notion of what you want to write about, even if it’s just writing about writing. You can always restructure, carve out huge chunks of dross, or slip in the good stuff when you have assembled the working material.
Elmore Leonard sets out on his writing adventures without sketching out a plot or storyline. If it works for him, don’t knock it. The dialogue is convincing and his characters evolve fully fleshed out by the end of his fast-paced novels.