I see a lot of metadata out there in the wild woolly world of repositories. Seriously, a lot. Thesis metadata, article metadata, learning-object metadata, image metadata, metadata about research data, lots of metadata.
And a lot of it is horrible. I'm sorry, it just is—and amateur metadata is, on the whole, worse than most. I clean up the metadata I have cleaning rights to as best I am able, but I am one person and the metadata ocean is frighteningly huge even in my tiny corner of the metadata universe.
So here's a bit of advice that would save me a lot of frustration and effort, and is likely to help the people who really need to read your stuff find it.
When you're doing keywords? Anything that shows up elsewhere in your record is not a keyword, okay?
Authors and other creators are not keywords, save for the rare case that the item is somehow autobiographical. Titles are not keywords. (Really. They're not. They may contain a keyword or two, but that's not the same thing.) Any search engine is going to turn up authors and titles that don't appear in the keyword field; trust me on this one. Likewise, if every single word in the full text of the item is a keyword, then nothing is.
The point of keywording is not to shovel in every single word that someone might conceivably search for. Leave that kind of indexing to Google and other full-text indexing engines. The point of keywording in this day and age is to distinguish this item from all the other items that look vaguely like it, to help folks who arrive there make the snappiest judgment possible about whether this item is what they need.
When you add keywords with a backhoe instead of an eyedropper, you are not raising the chance your item will be read or used. You are lowering it, because most people who arrive at the item will roll their eyes at the lengthy list of keywords and bounce right back out looking for something more targeted.
Keep your keywords to-the-point and as few as possible. This metadata librarian thanks you for it. So will your readers.