I have a tendency, more than most other physicists, to try to figure out everything all at once, before I publish. And even to try to figure out everything in my head, without pencil and paper.
It was pure guesswork on my part back in 1979 as to whether I would have the stamina to write, pencil, ink, letter, tone, and fill the back of a monthly comic book for 26 years.
What you do is, you have your drawing board and a pencil in hand at the telescope. You look in and you make some markings on the paper and you look in again.
I work pretty quickly. I'd probably draw somebody once or twice in pencil, then just go to ink. Not really care too much about it, and it just kind of worked out.