I use this in my planning phase when I’m a bit stuck, have lots of ideas and am not sure how to link the activities to the topic and make a coherent flowing lesson. I also try to tie in the homework at this stage so it links to the next thing or the previous thing we’ve studied.
It is a variation on the famous 5 minute lesson plan, I just couldn’t get all I wanted down in 5 minutes, this takes me a bit longer but it does make me observation ready!