Rather than a prompt urging you to write something new, this week's writing exercise returns you to something you've already written. I like that this makes you examine your work when it gets stuck, which is likely to tell you much more about your writing than examining the sections that flow with grace and ease. I also find advice that impels you to let go a bit as you write extremely helpful. Too often, we get mired in the crafting of small things (words, sentences) and we end up making tortured and stilted big things (paragraphs, chapters, books). Go on, get unstuck:
Find a section of your writing that has no energy to it and rewrite it as one long sentence. Be sure that the sentence keeps expanding outward, don't worry about it being a run-on, and just let it flow--642 Things to Write About by the San Francisco Writers' Grotto (Chronicle).