No we didn't. That's where the tricky math comes in. You need to add up the space for the bullnose, the pencil liner and the pinwheel . That determines the size of the mirror. Hope this helps. The border is applied, then the mirror.

Keep in mind that when you apply something directly on to a mirror that you will be able to see the back side from the reflection. The back of tile doesn't sound too attractive. Also, tile will be heavy. Instead, consider creating a frame out of flat wood. Then, paint it or decorate it to compliment your room and be sure to paint the back side as well. Here is an example that was made out of scrap lumber and then finished to match the cabinetry. If you look closely, you will see that the back of the mirror was painted black.