I just put all my picture in folders, I don't tag anything. I first sort by art style, as in western art, hentai or gravure pictures. Then I sort them by media type, as in video, image, flash game etc. Specifically for the hentai file, I have an artist file , a file for single images, one full of reference sites and saved .htmls because I have a bad memory for hentai sites, a file for canons, and a file for videos. The artists file arranges story driven work by artist, simple enough. The canon file is used for grouping art and hentai that has a common series, like Naruto, rather than grouping by artist. The images file is a bit tricky, because image downloads are a bit of a potluck. The image folder is organized into several groupings, I've been trying out different groupings and its still a work in progress. This is what I have so far. I have a folder for appearance, one for artists who draw single images rather than story driven work, one entirely for boobs (which I am attempting to sort by size, weird I know, but the folder is huge otherwise and I can't find images easily), a canon one for miscellaneous erotic game art that doesn't belong anywhere else, an actual miscellaneous folder which is full of downloads I haven't gotten around to classifying, one for outfits (sling bikinis, sweaters, tight shirts) and one for actions (titfuck, blowjobs etc). Usually I get my art and images from 4chan using downthemall, so I just make a new folder named the topic of the thread (eg. big boobs, sweaters, rozenweapon) and put the folder in the correct place afterwards. That's about as far as I have gotten into organizing my stuff. I also do this with my regular files because I just like knowing where things are. It makes life a lot easier. I hope this helps.