There's a famous scene in The Dark Knight where the Joker tells Harvey Dent about his lack of plans
"They're schemers trying to control their little worlds. I'm not a schemer. I try to show the schemers how pathetic their attempts to control things really are."
It's an interesting scene, not least of all because the Joker seems to have everything very well planned out: the bank robbery, his escape from prison, to the dilemma he presents Batman of Harvey or Rachel. While not directly controlling his worlds, his plans are flexible enough to achieve his ends.