For historical reasons, I do a lot of pre-planning in my head. That's how I work out what needs to be a scene and what should be off stage, also how a scene happens, where it starts, where it finishes and who does what to whom and how. But I hesitate to recommend it as a writing method because I learned how to do it during the tedious, routine daily walk to school, during which I would build long running day-dreams in my head for amusement. It therefore must have taken me several years to perfect my technique. This is probably several more years than anyone would sensibly want to spend mastering the method. *g*
After a while I could "edit" the day dreams, backing up if a scene didn't go right and running it again slightly differently until the story progressed as I wished and I could move on to the next scene. As my walk was about 20 minutes long and some day dreams got to epic lengths, I ran them in instalments. Some could take a whole week to run through from beginning to end. I finished up with a kind of library of them and once I had one perfected, I could run through it every so often, just as one would watch a video today.
I can't remember them now, but it's why I'm not good at sitting staring at a blank screen. If I'm not sure what happens next or I need to sort out a plot problem, I have to go for a walk!
There is a downside to this method though and I use it more sparingly now. Firstly the planned scenes can run too far ahead of the written ones. This causes frustration. Also they always seem better in vivid technicolour and full sense-urama in my mind, making the scene on the page seem flat in comparison. The final problem is that it is easy to fall in love with ones characters and invent scenes that are important to them, but not to the overall story. You have no idea of how the word count is going when the scenes are run visually in the mind's eye, so the story can easily get unbalanced.