For projects in general, I've really strived to give each a meaningful title that has a noun-sound to it. I then put that on a label to affix to a project folder.
Then any support material that leads me to the developing (AND completion!) of that Project like its e-mail's, brainstormed ideas from mindmaps, etc. go into that folder. When it's necessary to discuss, to move on that specific project, that folder is available, with all its reference material which somehow seems to have internal spirits that say action is forthcoming from me, my subordinates -- the external forces of the universe that cooperate with little me, perhaps?!
I'm really trying to adopt the mindset that projects are for me to complete along with any others I have to delegate parts and/or subparts to. Then it follows that countless hard forms like printouts from e-mail's as well as doodles of brainstormed mindmaps are support material, saved in one place (not scattered like the dashboard, the edge by the sink, coffeetable, backseat, etc.)
I got this strange insight after a drive one late from a client who said to me "I want some action." (I said to myself, she's right, so do I!) It haunted me then later nights on a 70's disco reliving program, hearing Alicia Bridges, a disco lady who added "I want some action, I want to live," from her solo single "I Love the Nightlife." (A nightlife? What a thing for me to have! I like how Ms. Bridges summarizes that she loves action, that she wants to give it and get some too.)
I've found it imperative to separate action from support materials. That way, my clients and I get to boogie.