A long time ago I read that if you are awakened and want to fall back asleep, you should picture yourself turning around, going through a door to your basement stairway and descending the steps towards the dark basement.
I tried forever to do this and couldn't, and thought it was something about this scenario specifically. But then years later, I learned about aphantasia and realized I can't actually picture anything at all. The doorway wasn't special.
Visualizing myself going through a doorway is difficult even for me. I think it's in part because it requires some creativity (compare "visualize yourself going through a doorway" as opposed to "visualize yourself going through the doorway of your childhood house"). The salient conceptual feature of a doorway is that it goes somewhere and so the prompt basically is asking you to imagine something without explicitly asking you. Even your example of the basement stairway is much easier for me to visualise, because the doorway has stairs after it.
Nope. Not doing that!
Sounds like nightmare city!