I decided to start a forum thread rather than hijacking the comments on the blog post.
I'd really appreciate some verbal guidance on how to accomplish Diane's very cool-sounding knot trick. Diane, I saw your comment in the thread, and thank you very much for the quick response! I'm still a little confused, though, on a number of points.
1. Does the top need to have a specific sort of hemline in order for this to work?
2. I'm still not really clear on how to do the knot. Where is it supposed to fall on the body? How do you each go about tying it? Is the elastic visible or hidden once it's done?

Thanks for your patience, guys.