I came across this tutorial for paper clips tonight and had to give it a try. I thought it was a great alternative to just erasing the "behind the paper" part of the clip. Just adds a little something, I think. This pic is at 100% on my last layout and it's not that noticeable when zoomed out. I had the opacity really low - like 20% - next time I might bump it up so it's more obvious when looking at the page as a whole.
She does the tutorial in PS, but I did this in PSE using the emboss style and adjust opacity levels. Really easy. Tutorial here: http://digitalscrapbookpages.com/ps-tutorial-showing-the-bump-for-the-hidden-part-of-a-paperclip/