You're strumming along and somehow your pick loosens from your fingers and falls into the depths of your acoustic guitar. Instead of shaking your instrument like a madman, grab a pencil.
No, the pencil isn't for scribbling heartfelt lyrics. You're going to use the eraser end of it to pin the pick to the back of your guitar just below the hole where all the sound comes from. YouTuber guitarplayeru shows you that once you've got it pinned, you can just turn your guitar so the hole opens up downward, and pull the pencil away.
The pick should fall out of your instrument -- or at least to the strings where you can flick it out -- and you can now resume your jam session. Alternatively, you can put something sticky on the end of the pencil -- like tape or gum -- and try to pull the pick out operation style.