Switching to hand writing in a notebook has genuinely changed how much/easily I can write. I automatically view it as a draft, so I don't edit myself so much (compared to writing on computers where I get super stuck writing and rewriting the same bit when I should be moving on.) It's especially useful for microfics. (Although obviously ymmv. I used to write newspapers and stuff by hand as a teenager, and I wrote my first few professional pieces by hand too. I don't know why I stopped! Now I have tons of notebooks again and it's awesome. Best thing is having an excuse to buy nice/cool/cute stationery hehe :3 )
Yup, nothing like cheap binder paper for scribbling out whatever wants to flow from my brain to my hand. Any notes for filing away for later go on a reinforced paper. The first step is write (you're telling yourself the story), the second step is rewrite. I want to remind people of the commonplace book, think of something like a paper blog where you put down anything that inspires you or that you want to keep track of, and art journaling if words themselves aren't coming. I have what I call my 'tornado of thought' book where anything is allowed to go in to it. No one else has to see it unless i want them to so it gives me a private space to work out ideas.