Summarize:

Take apart a pair of cheap sunglasses and use the parts to create a template for your wooden sunglasses. An easy way to do this is to lay each part on a photocopier and make a copy. Alternatively, you can try to trace out the shapes of the parts using pencil and paper. Cut out each part of the sunglasses from your paper template. Also keep the lenses from the cheap sunglasses to use in your new wooden pair. Remove them by pushing them gently out. Each block of wood should be approximately the length of the cheap sunglasses. Don't worry about depth, as you'll need a margin of error. It's quickest to use a scroll saw or some other powered saw for this. However, you can use a coping saw to do it by hand. It will take longer, however. Place the lenses on top of the openings where they should go and trace their shape with a sharp pencil. Use a drum sander attachment in a drill press to sand near, but not over the lines you just traced. You could also probably do this with a rotary tool with a drum sander attached. The reason you are doing this is to leave a groove for the lenses to sit. . With a wood chisel, cut away the excess wood from the back of the frame. Make sure you don't cut too much away. Next, observe the curvature of the original frame, and attempt to copy it on your wooden one. You can use a drum sander attachment on a drill press to do this, or a rotary tool with the appropriate attachment. At this time, you'll also want to sand down the frame and the earpieces until they are smooth. You can do this using a combination of a rotary tool, wood files, and sandpaper. For this, you can cut away the hinges from the cheap sunglasses you've been using. You can also cannibalize the hinges from another pair that no one wants. Cut away little cavities approximately in the shape of your hinges in the frame and earpieces. Then glue the hinges into place. You'll need to use clamps to hold them in place while the glue sets. Leave the clamps on for about an hour. Attach the earpieces to the frame using the screws that came with the hinges. With a piece of cloth, apply a coat of mineral oil to the wooden frame. This is helpful because of the amount of time the frame will be in contact with the skin. Finally, buff the frame with beeswax for a smooth finish. The final step is to snap in the lenses for the last time. Don't force them in, or you might break them. Simply push gently until the lenses pop into position.
Make a template. Attach each shape to pre-cut blocks of wood. Cut away the shape of the sunglasses. Fit the lenses. Remove excess wood and shape the frame. Make the hinges to attach the earpieces. Apply mineral oil and buff with beeswax. Pop the lenses into the frames.