One of my myspace blog readers commented on the first few points, and I think they had a great point to add to this list...
"One thing I try to do as well is keep in mind the Hero when developing the Villian and vice-versa. Making them equals in many ways adds to the tension especially in the final battle, and opposites in others creates a certain dynamic. Why is the Hero the only person who can counter this guy? M. Night's "Unbreakable" is a wonderful case study in this.
Posted by Lenora "
(posted here with permission)