Working on Soldering Skills

I have been battling a flu bug, but it hasn't stopped me from soldering.  I hand cut and soldered this bezel and added the brass stampings and a found brass piece to frame it all in.

I am going to add my favorite Madonna and Child image and call it "A Pummeled Heart".  I also have been experimenting with soldering brass stampings and bezel cups.  It has been very difficult.  As soon as the solder gets hot, the pieces want to move all over the place.  I am wondering if there are some sort of clamps I can use to keep them in place.