Place it immediately after the failed moment in an edit, then follow it with Vine Boom for extra impact. Open with SpongeBob Fail when the miss needs a bigger build-up first, and keep it as the final reaction so the joke closes on the put-down.
About this sound
This 3.8-second clip delivers the line 'You're not very good at this' in a flat, mocking spoken voice, with no music or other effects behind it. It lands as a dry, teasing put-down, funny because it sounds calm and matter-of-fact while calling out a clear failure. The tone makes a bad attempt feel smaller and the moment feel lighter, turning an embarrassing miss into a quick joke.