Continuity is important to novelists. It's jarring for a reader to find that the father is accidentally called by his son's name like I saw in a historical novel recently. Continuity errors creep in so easily, especially if the writer works across the entire manuscript instead of linearly. I've done it and I'm horrified when I catch those types of errors.
I've got a small spiral notebook that records all the names I've used and a brief description of who each character is, but still errors creep in because I can't remember when I've updated it. Sometimes a minor character shows up later in the book and a new, more apt name shows up with them.
What's your techniques for catching this type of error?
How do you keep up with all the people who populate your WIPs?
Do you have any suggestions for the rest of us, other than rereading closely?