Fair use template
Take a look at RationalWiki:Upload then. It has specific pages for different types of files, including one for your own work which explains the various licenses, and only lists relevant ones.
I didn't know we had that page. Which is weird, because I just checked, and we do indeed have it linked in the green text boxes on the upload page. I suppose my eyes just sort glaze over them, since I've been uploading images for a while before its existence and didn't figure I needed help. That's what I get for being arrogant.
For a time the link in the toolbox pointed to that page instead of Special:Upload, but people didn't like it or something, I guess because it required them to read instructions.
The problem with all these pages, including the green boxes on Special:Upload is, that although they explain everything nicely, they're huge walls of text, so no-one bothers to read the instructions.