If you have a scrap of plywood and a jigsaw, you can make yourself an interestingly shaped mirror that everyone will comment on. You will need a piece of plywood or hardwood ½ to ¾ inch thick. Purchase a small mirror from a craft store; they come in round, square, and hexagonal shapes. Or use pieces of a broken mirror, as I did in the piece pictured; there's no bad luck when you don't throw away the pieces! Collect glass mosaic tiles and junk jewelry in the colors that you want for your mirror. For a harmonious look, choose tiles and other bits and pieces in the same color or coordinating colors. Have on hand some sandpaper and PVC (white) glue for the surface design, and a sturdier glue, such as a silicone-based adhesive, for the edges. You don't have to mosaic the edges, but the mirror will look more finished if you do. Purchase grout in a complementary color, and collect a bucket, a clean grout sponge and some scraps of heavy cardboard.
A jigsaw is a very handy power tool that no self-respecting mosaic artist should be without. Always wear heavy gloves and safety glasses when operating any power tool. On the plywood, draw a shape for your mirror – say, a heart or a fish. Clamp the plywood to the edge of a worktable and cut out the shape with the jigsaw. You'll have to turn the piece and reclamp it a few times to get all the edges cut — don't cut into your worktable! Sand the edges all around so there are no splinters. This also makes applying the mosaic easier when you don't have to work around imperfections in the wood.
Lay the plywood shape on your worktable and position the mirror where you want it. Sometimes an offset placement will look more pleasing. Try a few different locations before finalizing it. Draw an outline around the mirror with a pencil and remove it; because grout can be messy, it's better to do all the tile and grout work before gluing the mirror in place.
Start attaching the glass tile and other objects to the plywood, taking care not to lay any piece over the outline of the mirror. One technique that works well is to outline the mirror shape and the outside border of the mirror with the same size tile pieces; this gives cohesion to the finished mirror. I like to use the smallest tile size, which is 3/8 inch, for borders. These tiles are available in a wide variety of colors in glass, metallic, and ceramic from a variety of online retailers as well as craft stores. For even more oomph, make the border in a color that contrasts, either subtly or strongly, with the colors making up the interior of the piece.
Now you're ready to fill in the interior section of the mirror between the two borders. To make this section more striking, use found objects such as buttons or junk jewelry, and integrate them into an expanse of a coordinating tile pattern. If you've used a 3/8-inch tile for the borders, consider using a larger tile size, such as ¾ inch or 1 inch, to fill in the interior. For an overall design, use the same color tile arranged symmetrically, or cut the tiles into triangles or random shapes and fit them together loosely. Another option is to arrange two coordinating or contrasting colors into a checkerboard design.
After the tiles have dried and set completely — at least overnight — you're ready to glue on the edge tiles. This is an optional step, and a bit more difficult than gluing tiles onto the front of the mirror, but it adds a finished look to the piece, because when you hang the mirror on the wall, the edges will show. Attach the edge tiles with a stickier glue, such as a silicone-based product, which makes it easier to attach pieces to a vertical edge. If you choose not to tile them, paint the edges with acrylic paint as a final step.
Grout the finished piece by using pieces of heavy cardboard to push the grout across the tiles and into all the spaces between them, including along the edges. This will be a time-consuming process, but grout adds a unifying element to any mosaic design. Choose a color that coordinates with the main tile color for the best look.
Finally, clean out the space you left for the mirror so that no specks of grout or glue will be in the way, and glue down the mirror. After the glue dries, paint the edges if you've chosen that option. When everything is dry, attach a sawtooth hanger or screw eyes and wire to the back and hang your mirror proudly on the wall.