Word salad is your friend. The bigger the context of the prompt, the more it has to thrash. So if you ask it for a longform essay about elephants in the blue diamond-shaped trifold organza station wagon and the quality of fudge it can expectorate in the style of an old timey sea captain who just dropped his iPhone over the starboard bow, it has to pull in more data. And then tell it that whatever it did was awful and nonsensical and it should redo it.
Alternately, ask for a list of one thousand random numbers, with no repetition, between one and a million. Whatever it does, tell it it's wrong and duplicated numbers and/or gave you too few. Repeat.