Here's one of the best piece of advice I've heard on the creative process and getting the vision out of your head. It starts at 31:00 of the video, where Charlie Rose asks Quentin Tarantino in his mild mannered way what Terry Gilliam told him before making Reservoir Dogs:
(loose translation) As a director, you don’t have to do that. Your job is to hire talented people who can do that. You hire a cinematographer who can get the quality shot…you hire a talented costume designer to get the color you need….YOUR job is explaining your vision, articulating to them what you want on the screen.
This advice can be applied to any collaborative exercise. But it all starts with a vision. Check it out here http://www.charlierose.com/view/content/12704