A good vice has a clamping jaw that can hold ANYTHING while you wail away on it. The problem with that is the damage that can be done to the object clamped in the vice.

Here are my vice jaws:

Jaws of Death

To prevent damage to small items, I cut a couple of pieces of 3/4 x 3/4 aluminum angle (the square kind, not the structural kind ) to clamp without damage

Jaw protectors

The problem was that these babies were ALWAYS hitting the floor while I was trying to insert the work. So, a quick trip to the local stationary store got me a rubberized magnet (used to make business cards into refrigerator magnets) that I cut into a couple of strips and glued to the top of the jaw protectors. Voila!

Magnets glued to underside of jaw protectors

Cool.