I saw that, too. This is why i was asking. ;)
Here is how i do it:

I have many difficulties to divide things up. Because i am self-employed and the line between me and my work is very blurred. Sometimes i can't really say if that is work i am doing for me or if it's something i am doing for someone else.

I decided to divide my files in 4 folders. In, Pending, Out, Archive - Archive is the point.

I my sidebar there are sitting 4 folders, waiting for files i give' em.

Here is how it is by now:
1. Things coming in (Inbox) - everything - Downloads, Mail Downloads etc. EVERYTHING which produces digital data
2. From there i put files where they should be. i divide them up (with Spotlight comments) in: idea, preparation, pending, procrastinate, wait for. I use Hazel to find files i am currently really working on and which i procrastinate and don't work on. (especially some songs for a new album... *argh* Often i have to work for money and not for my music.)
3. When something is very old it get's moved automatically to archive. So that i can see "Oh there's another one of those ideas which were just ideas."
We are now inside archive. I have a special folder called "Music" there. Where i put all of my music in. Done projects which i can't assign to a client. Artwork for the music, etc. But there are many other folders. I decided not to split "Me" up again, as i did before, so i have folders like: Clients, Programming, Computer & Software (mainly PDFs about ...), Friends, Scripts & Snippets, Homepages, Mind, Office (eg. all of my invoices) ...

I feel well organized this way but i thought there is maybe some smarter way...

Thanks for your answer