I've been told for years about my shitty posture. I'll occasionally take steps to correct it, but I always seem to slump back into my previous habits.
Drawing for me is actually one of the least comfortable things I do. Typically when drawing, at least in analog form, my face winds up a mere 4" from the page, so I'm incredibly hunched over. To fix my drawing posture I bought a balance ball, as seen in this comic, however I wind up slouching on that too, which it turns out is probably even worse on the body.