I sew those loopies together and then use elactic thread to wrap all layers.
I've never sold any loopy bows on eBay (tried several times but all failed). Not sure where I did wrong. And it's very time consuming (loopy and spike) so I gave it up.
One of my loopy bow: http://www.auctiva.com/hostedimages/...rmat=0&lgdin=1
The simple one would be like this: http://www.hipgirlclips.com/store/in...products_id=93