Mike Leigh, he of Naked and many other fine films, used an open-ended approach to many of his films. Rather than write a script, he'd have actors improvise on a number of basic themes and with some rudimentary notes about what kinds of characters they were playing. Over time, the scenes would develop a direction and force of their own, and from them he would knit together a more formal story. But the open-endedness, the willingness to trust his performers (and for them, in turn, to trust him), was paramount.
As of late I have come to see the way creative types treat their ideas might be better akin to this sort of management — one where the ideas themselves are full participants in the act, and not just ingredients in a stew or parts requisitioned from a warehouse. I 'spect a lot of that's been coming out of the reading I've done as of late vis-a-vis theater and acting (e.g., Tadashi Suzuki), and I'm finding the advice in those venues a whole lot more helpful and relevant than anything from all those dismal how-to-be-a-writer books. Most of the truly useful advice I've received about writing has not been from other writers, but rather from creative people in other disciplines — the music producers in Behind the Glass, for instance, or the filmmakers and actors profiled in Ebert's interviews.
Let me stop short of saying that everyone else could do as well, or better, if they ditched their copy of Finish Your Novel, You Bozo and started reading Stanislavsky. But I'll stick my neck out far enough to suggest that every creative discipline is ultimately closed-ended in terms of what it can teach you about the creative process. Not everything's going to map to everything else, but there are some insights you just don't get from your immediate peers.
I'll be spending some time in the coming year going into this in greater depth, and I hope with more valuable insight to be gleaned from it.