Apologies on this exercise as it did not get said in the episode, but that's why we have a shiny new website!
For this writing challenge, with the idea of throwing out your first bunch of ideas to cut through the collective unconsciousness, come up with ten initial premises for a story you think you might want to write. For example " a man wakes up in an unfamiliar place, realizes he is trapped in an underwater city." Then, keep whittling those premises down until you have only one that seems truly in your wheelhouse.
Happy writing!