i don't know how others do it, but i lay the clip over my paper, use the lasso tool to cut away the part that i want "behind" the paper and then paste the part i cut out onto a new layer. the new layer i place under the paper layer and then match it up to the other part of the clip. this looks especially good with vellum because you can see the other side of the clip beneath the vellum. i hope that made sense. here's a layout i did to show you what i mean
http://www.scrapbook-bytes.com/galle...cat=500&page=5