that's a great tutorial.
I made my daugher a tutu the other day for pics. I started out doing it this way but it wasn't fluffy enough for me. so i just tied it on with a double knot. (first knot loose, second knot tight) I used a ton of tulle but it was nice and full just like I wanted.
I bought the tulle on a roll in the bridal section of joanns. I just had to cut it to the length that I wanted. Here's a pic of my youngest dd in her tutu.