[LVL ED] How do you make a well detailed level?

[Radical Batz]

I am trying to make a very good detailed, realistic level but I'm all out of ideas, I'm scared if I steal somebody's idea because there's this custom story which has this level that i'm really addicted too and I wish it was my level because it was so detailed. I am trying to make my own detailed level but I fail a lot and it becomes a boring level. how do i make a very well detailed, scary,realistic level that makes the player want to keep playing and enjoying the environment? pls help guys. I wish I could make a level which is similar to the prison in the original amnesia but that's copying ! HEEEEEEELP!!! If you make really awesome detailed, scary, realistic levels/maps then pls tell me how you did it. plssss