I've been hung up for four days on a scene shift. A conversation is cut off by a scene break. It continues right after the break, with the same ensemble in a different place. Easy cinematic effect and a basic writing device, and I can't make it work smoothly!
But last night I saw a way to interrupt the flow to good effect--a better result than I'd hoped for the other way. I woke up without forgetting it, and after a few false starts I've got a hundred odd words that I like.