I found this article which has some good pointers:
http://digital-photography-school.co...onal-hardware/

- I've implemented #2, which is to increase the size of the cache folder. I haven't tested it fully yet to see if it has helped, but a lot of people say that it does.
- I haven't tried point #7 yet, Render Previews Before Editing, but I'm interested in seeing what happens when I do.
- For point #4, they don't mention one thing I found elsewhere: I changed the "Automatically Discard 1:1 Previews" setting to Never. It's supposed to help a fair bit. I'll keep an eye on my disk space but I've got a fair bit of room.
- I'm definitely in violation of point #8, keeping catalog sizes small, but I do cull images as much as I can and optimize the catalog frequently.