For fast, physically intuitive, flow-of-thought expression, there’s nothing like pen and paper, for me.

I throw away almost all my handwritten notes, because of the downsides: illegibility, unsearchability, physical bulk.

But the qualitative difference of thinking or reading +/- handwriting is huge. I don’t get caught up in editing. I can draw diagrams easily. It slows me down, makes me dwell on an idea while I’m writing it, and thereby physically calibrates my thought process.