I like to switch it up. When I write longhand it's usually on scrap paper or in old spiral notebooks leftover from my kids ... you know, the ones with a few pages left.  It's a green thing. I use those notebooks to scribble out ideas, play around with words, experiment with rhythms.  When an idea starts feeling like a story, I open up a computer document and mess around there.  But then I might print it out – always on scrap paper, there's that green thing again – and revise and rewrite by hand. Then it's back to the computer. I go back and forth like this until I think it's done.