Mostly laptop, but I also added phone and paper.
My usual process is to write a chapter in Obsidian (which I like because I've developed a weird sort of quick draft/expanding outline method that uses the Markdown features). Then I copy it over to Google Docs, fix the formatting a little, and do a final editing pass by reading through it on my phone. Then I upload it to Royal Road, fix
more formatting (horizontal lines really shouldn't be as complicated as they are...), and copy it over to Scribble Hub.
I use pen and paper once in a while when I'm stuck on a story problem. Something about writing by hand loosens up my brain gears and lets me untangle and develop my thoughts in a way that typing can never quite replicate. Maybe it's the magic of sparkly gel pens.
