My favorite writing prompt came from a barista at Starbucks in Austin
She handed me my latte with a napkin that said 'write about the 4th person to enter a diner at 3am' and that one line sparked my best short story, so how do you find prompts in everyday overheard conversations without forcing it?
My buddy got a killer poem out of a Walmart intercom announcement about a spill on aisle 7. He wasn't hunting for it either, he just wrote down the exact words in his phone and the weird rhythm of it stuck with him later. The trick seems to be carrying something to jot in and not judging whatever catches your ear.