I have a threshold that if I surpass quickly becomes a chase. My solution is to go to bed at around 8pm and read until I fall asleep, which is sometimes immediate but never usually much past 10pm. That way, I can wake up fully refreshed at 4am, or I can sleep until 7am if I need it.

I use melatonin to reset my sleep cycle if I mess up and end up staying up all night. A mg or two at around 5pm helps me back into my target range, and from there I usually don't need it.

Routines are important. If I didn't try to actively control it, I'd stay awake until the sun came up and then sleep until noon, and I much prefer working in solitude when I first wake up than when I'm mentally fatigued at the end of a day.