I am such a cataloging nerd that I am checking the cross references in the catalog to make sure that all of the genre/form headings from LC are in the authorities database. Actually, I think this will help patrons when they are looking for materials of a certain type. The headings I've checked and added as necessary so far are types of: Cartographic materials such as Globes and Relief maps, and for Law materials such as Statutes and codes and Law for laypersons. There approximately fifty individual types of law materials and about a dozen cartographic materials headings.
The next group I will tackle is a big one--Motion pictures. I have many of those, e.g. Science fiction films and Comedy films, already in the authority file, but will be double checking to make sure all legitimate references are in the file. There are approximately one-hundred different film genres listed in the LC Authorities database.