Here's my sewing machine full of pink poof. After scouring the 'net for tutu instructions last year, I finally came up with my own way of bunching the tulle and stitching it down in sections. I find it's more durable than a single or double round of attached stitches and much faster than knotting, which I found always bunged up my elastic. The downside is that the tulle is forever pulling out the thread from my needle.
And here's the finished tutu. I debated about adding some bling, but left them off just to be safe.