One thing I've done is create a "color clock" using a smart bulb that changes color based on a daily schedule. So at 8:00pm the bulb has a dim orange glow, this changes to dim red glow at 9pm and then turns off at 10pm (sleep time). Its a really nice relaxing way of ensuring a regular sleep pattern (no longer clock watching etc).
That's a great idea! I'm kicking myself for not thinking of it because I did the opposite for my toddler to let him know when it was okay to get up in the morning (otherwise he'd be up before 5am). I had a dim red as a whole room nightlight that transitioned to dim yellow-green to signal that is was now okay to get up.
I have a Philips Hue bridge plus Hue smart bulb.
The Hue system has an "Automations" function you can configure via their phone app.
So I just created a set of custom automations to change the bulb color on a set daily schedule.
There are lots of other ways of doing this depending on your setup. I think you could probably use IFTTT or Zapier to do the same thing with other brands of smart bulb.
I have to set an alarm for bedtime, but I still struggle with being disciplined about it.