I don't have any of the images that I download from Pixiv saved on my computer. XD Once I download a picture from Pixiv to upload onto Shuu, I delete it right away.
Same here. But if I really like the picture, then it goes into my "Screensaver" folder to be displayed in a slideshow in my screensaver. Sometimes I leave the file name as the Pixiv id number but sometimes I rename it to something descriptive, like "Chibi nurse miku", "Viral genderswap", "Angry winry animation", "chinadress glasses icecream", "Wriggle hug butt!
If I hit my upload limit and still have images I want to upload later, I'll save them to my desktop with the artist name.
It seems that making a lot of folders is common. On her computer, my BFF has tons of folders sorted by series and then within each folder there is a yaoi subfolder.
Mami chibi drawn by Jiino, animated by me. | Sophie sig by Misuzu | My Anime-Planet page
but you know, not every image has a source and not every character has a name :3