I regard pixel art VS CG to be an unimportant distinction (just a difference of exactingness), so I have both in the same directory (I don't have folders on my computer), I actually haven't done a lot of pixel art this year, though it appears I have consistently finished all but one of the pixelled pieces I started
Under my Art directory, I have a directory 2007, and will be changing soon over to 2008. In that directory, all picture files are 'unclassified'. I have a gimp plugin that saves the current image with a name like sketch122507-00.xcf.gz in this 'scratch' area, which I usually use when saving an image for the first time. (the date is meant thusly to be the date of creation rather than the date of revision -- I care more about the date of creation, which is not reliably preserved across OSes/filesystems otherwise.
If they turn out interesting, I rename them to something more descriptive -- like 'crazy-berry.xcf'
and later move them into a subdirectory, also usually rerendering them.
Each directory may also have a HISTORY subdirectory., which tracks old revisions of the history of images (depending on whether i use my 'save history step' plugin for some of the images in that directory.)
I also have a XXXXcont directory, in which I place promising WIPs from the previous year. (XXXX being a year number)
Elsewhere, I have refs, which are more or less independent, organized by type of pixelart (portrait, sprite, bg, tiles, ..). And which I more or less don't refer to.-- pretty much only when I'm looking for a technique/variation to render some particular thing.
I write about my art, techniques, HOWTOs, links to references... in my art journal (actually a TiddlyWiki (http://mptw.tiddlyspot.com
). I also use my art journal to plan and coordinate my art.
At the end of the year, i:
* Name and classify anything that I can
* Delete clearly insipid or otherwise cringeworthy drawings
* Transfer promising drawings to the next year's XXXXcont directory
* Move the sketches that remain into sketch/ directory (remembering to move HISTORY entries alongside them)
* Save PNG versions of images where needed, in order to...
* Mention any good images I've been tardy in mentioning in my private art journal.
I've been using this system for about 13 months