Here (image 2) I've added more refinement to the face and glued the oval piece of plywood to a larger rectangle which will be the backing to the entire piece as well as a sort of built-in frame.
The next image (3) shows the face surrounded by all the materials I'll use to define and decorate the face: The material just to the lower right is a piece of 2-inch sections of honey onyx tiles - the same material that my brother and his wife used in their bathroom; I got some of that in order to match the colors in glass. I've got four colors of stained glass arranged at the top of the image coordinated to the onyx; and at the left are various odds and ends such as gems, shells, and glass beads and tiles, all in similar colors.
I started setting the darker areas of glass first (4), but later (5) removed areas in the cheek to show more contrast. I also didn't like the hard line around the edge of the face and above the upper lip (in the photo it looked like a mustache, so by #6 you can see I changed the mouth!). In every work there is at least one area that I have to scrape off and redo. In this one I also later changed the upper right treatment above the forehead before I finished. Taking photos also alerted me to the fact that the cheeks were a bit too rounded-looking, so I added more hollowness by darkening the glass pieces at the lower left and right - you can see those changes in images 7 and 8.
I had to make many decisions about the border pieces, and the photos helped immensely with those in terms of balance and weight. I found myself taking a photo every time I arranged a few beads or tiles and checking the layout in the viewfinder. There were many test shots between image 8 and 9, and the final result, shown in the last image.