HI Sensei
I've just found your thread (great thread) and would like to leave valuable info.

About a year ago in a lucid that i've had, I came to the idea to spawn a marker from my pocket and write an L on my hand (so I dont get distracted while in the dream and lose my lucidity).
The interesting this is,
After that lucid ended, I woke up, went to the bathroom, drank some water, stuff like that AND when I fell asleep again I found an L on my hand in a NON lucid dream, and I instantly became lucid.

I believe dream world is more or less consistent, as in the past I've had about a week time of the SAME dream town every night over and over.
I hope you can make something out of this.
Cheers