I used to do something similar when I was a kid; I would look around the room and see what detail stood out to me. This is a bit easier to do in a classroom where walls are a main source of communication. I still do it with public art, people in passing cars, and stores. I just kinda look around and see what jumps out, then make a note of it and use it as a prompt later. It works well with my over-active brain.