Put it at the end of a failed attempt, after the mistake has already landed, so it closes the scene instead of starting it. Follow it with Sad Violin for a drawn-out ending, or lead into it with Sudden Suspense when the failure is still building.
About this sound
This clip is a run of slow, plaintive cat meows repeated over about nine seconds, with each miau sounding more downcast than the one before it. It gives a listener a soft, comic sense of defeat, like a small pet giving up after being told no. The sound works because the sadness feels gentle and exaggerated at the same time, turning a small disappointment into something tender and funny.