Oh goodness. I just found this one in my drafts dated back in July of 08! For some reason I didn't include any step by step pics. Oh well, it's pretty self explanatory. Enjoy!
Make your zig zag part first. Then add the knots one side at a time. Add the ends from the previous section to the next knot all the way down. Pull everything together at the bottom and make some kind of a messy bun. (Just make sure to add an elastic at the bottom of each knot. Otherwise they will come undone.)
I remember this picture, lol. She was trying to blow a bubble! :)
Try not to make everything too perfect. Part of the charm of this style is the messiness!
I also found this extremely old video showing how to do a knot. The sound stinks and it's not the greatest. It was actually taken for a different style that I lost the pictures for (yes I'm really organized) but the concept is the same. You get the idea, right?