For years and years and years, well before I became a quilter, I would doodle what I now know as a "meander" pattern, and also a lot of swirls.
When I started FMQ, both of those patterns have come to me very "naturally". I can meander and/or swirl all day long, any size and it comes out nice and consistent and I rarely back myself into a corner. But something like feathers...I'm terrible at those. Jerky, lopsided, uneven...I still need a LOT of practice on those.
So I think doodling is VITAL to good FMQ skills, and I really don't think the scale matters. I think the figuring out how to get from point A to point B to point C without getting stuck, and getting your hands and mind used to the various shapes, is what is the most helpful about the doodling.