Hm...
I don't know if I have a pre-bed ritual. Last night, I worked until 10:30, then went to bed. The night before, I took it easy, finished work by 8, watched TV with my roommates, then came up to bed.
I also run a TV show or movie on my laptop in my sleep, otherwise I can't fall asleep. It's usually something fairly neutral that I've seen many, many times before. Lately it's been Futurama, but it's also been other shows, like The A-Team, Airwolf, The Good Guys, Psych, et al. Something I've seen dozens of times. It's a bit weird, but that's the only thing that's worked for me for the last 10 years or so. Before that, it was music, but I find music harder to focus on, since there's no set start and stop points for me to zero in on and drift away.