I thought it was possible to make a "blank" clipping (via an Add Clipping button) to which we could cut and paste something from the web, etc. Unfortunately, I don't think this is possible now.
I love the feature in OneNote (and maybe others) that automatically adds the URL where the "clipping" came from. would be awesome to get the same functionality integrated in Clippings.
One workaround I am using is to find a scripture my web clipping would relate to, right click, add a clipping and paste my text. There is an extra step involved, but the added benefit to this method is that a Bible reference tag is automatically created. I always try to add several more tags to facilitate future discovery of my web clipping.