If it's not going to be an overwhelmingly large place for icons (ie. just for you to post your icons and not a big community) I think general tags are good. I also like to see tags for actor names, because if you're looking to see if a journal has someone specific that makes it a lot quicker. I also find show/movie tags helpful and, as for visible features, I'd say you could either take them or leave them depending on your preference, but I know some people really appreciate seeing them (especially if they're looking for piercings, tattoos, glasses, etc.)