The writing process/practices I currently use I've had for over a year, and it's easy for me to forget that the way I do things is really different from the ways of other writers (I love hearing about other writer' processes!). So I thought I'd share today one way that I've found that helps me to find focus and not ramble (quite so much) while I write.
I'm somewhere between a plotter and a pantser, meaning that I have no more than a vague idea of the middle and end of the book when I begin, but I outline each scene before I write it. I outline two or three chapters ahead, but never farther or it falls apart. Before I start a scene I'm usually carrying the idea of it around in my head the in days before, wanting to write it, and I'll start writing the scene in my head. When I start writing in my head then I know I'm in a good place with the project and I am VERY HAPPY. I imagine the dialogue, especially. And I jot it down.
Going into a scene knowing what has to happen and what information has to pass between Character X and Character Z is very helpful, but knowing ahead of time that one beautiful sentence that shifts the balance in that chapter? For me, that's gold. The one sentence/paragraph will be what I work towards for the entire scene, and I can make sure I don't stray from the goal of getting to a place where it makes sense for character X to say that.
For some people, knowing the most interesting line(s) ahead of time might take the fun out of it, so this might not apply, but it might just help you to stay focused :D Do you have specific ways of preparing to write?