Updating LibraryThing

I'm trying to add the books I've read to library thing, and also add some meaningful tags about the themes I find interesting. It's been so long since I've read some of them that it's hard to remember which book had what . . . it's funny how a single author's works can start to merge in my mind. It's also hard to go back and add tags to the books I've already entered, not to mention reducing the number of words in my tags while retaining meaning.