I finally perfected a DIY lighting scheme for shooting macro photos and tested it this evening. Made from an old light modifier for my flash and popsicle sticks, it satisfies all of my requirements; lightweight, easy to set up and tear down, easy to transport, does not prevent me from getting close to subjects, and, most importantly, produces soft light.

Attachment is by way of velcro to my flash head and macro lens. The top half is a reflective white surface that bounces light to the bottom half diffuser. When removed from the camera, the assembly folds flat. The angles have all been calculated to maximize light intensity at the diffuser.