I am using tags for both my graphic work files and fonts
I am tagging all of my portfolio work to make it easier to find specific kinds of jobs, as for my live work, rather than portfolio selected pieces, I'll probably be using the same tags on new work from now on.
I have also been tagging the image library for my main client, especially useful say when airport pictures are in separate folders (filed by product category), now I can find all airport pictures no matter where they are filed physically.
As for fonts, I have keyworded all fonts using more or less standard font classifications, and also used a program called HoudahSpot no sync mavericks tags with open metadata tags for added compatability. All I need now is a font manager that can read tags and let me use all that work to search fonts by type, without reclassifying all over again.
Alas, no font manger out there reads mavericks or open meta tags as yet, Fontcase looked promising, but that has now been discontinued. FontExplorer allows classifying fonts (as does suitcase, but non of them read tags, mavericks or open metadata tags