When working on a piece you can place it on the jack. I prefer to hold the piece in my hands that way I can move it around a lot easier.  Hold the part and adjust the height of the lap jack until the piece is in focus.  Then when adding wire, you can generally hold the wire like a pen and you don't want to brace up against the ring or hold your hands together while you're adding the wire.  You're going to want to place down put a little bit of pressure on it you don't want it lying down flat.  Let's just put a little bit pressure like your writing on it.  Now you can place the part on the jack for added stability or you can hold it in tweezers, clothes pins, or pliers. When holding multiple parts together you can use wax, crazy glue, invisible tape, or any contraption that you can come up with.