Picture of Pallet mosaic mirror
I had picked up a pallet the same kind as used in my other Instructable
Thought it would be nice to have a mirror with some tile on it for above the fireplace, so on I went selecting tiles from my collection and making a pattern that is semi symmetrical with minor differences. 
I used an all purpose glue to adhere the tile onto the wood and the side of the mirror, keep in mind that if you are glueing onto a mirror you will want that glue to dry CLEAR.
Went out to a few garage sales on the hunt for a mirror within a certain dimension and built around the mirror.
Used tile grout picked up at a garage sale as well. 
Tiles can be chosen according to the other colors within your room or space. 
Just something fun that I took on as a small project.