When I sit down at the typewriter, I write. Someone once asked me if I had a fixed routine before I start, like setting up exercises, sharpening pencils, or having a drink of orange juice. I said, "No, the only thing I do before I start writing is to make sure that I'm close enough to the typewriter to reach the keys."
I type 90 words per minute on the typewriter; I type 100 words per minute on the word processor. But, of course, I don't keep that up indefinitely - every once in a while I do have to think a few seconds.
Whenever I have endured or accomplished some difficult task -- such as watching television, going out socially or sleeping -- I always look forward to rewarding myself with the small pleasure of getting back to my typewriter and writing something.