hmmm. that's a very complicated question. i'm compulsive so i devise a new system every couple of months, this time it's going to be first by occassions (film caps, public appearences, photoshoots, etc.) then by year. and then i tag every picture with the colour of his clothes, his hair, favourite clothes etc.

it's going to be awesome, until i think of a better system 
p.s. i know

You are awesome. You and all the others with organized PB accounts. I don't even have any such thing. I have all the pics in my computer is all. (Folders are systematic, but not necessarily the pix in the folders. At first, all my BBM caps were totally individually organized with a good system, but not Heath and Jake pix.)
On these threads, I'm a saver, not a poster. That sounds kind of selfish, that I receive but don't give. But I'm sure there is some psychic justice there -- we all have our talents. So, when I want to post a pic here, I have the "chore" of looking through all my thumbnails in my computer and uploading it to PB at that time. Mostly my BBM-PB has things like group gathering pix, b'day cards or meet logos, stuff like that. Sorry, OT.
Anyway, doing and redoing your PB systems is as good an occupation as any, if you ask me!
kathy