I am working on a project that will require some creative shadows.  I can “build” a an actual object to produce the shadows that I need, but since they will not be seen in the actual renders and would add polygons to an already complex scene, I would like to try creating my own gels to get the lighting effects I need.  Daz has some really nice looking gel packages, but I need something a little more custom.  Can anybody tell me how to do this or point me in the direction of a good tutorial?

Thanks in advance!