Let the tile dry overnight.
Then do a transfer of your image (photo or any image you like) using mod podge or golden gel gloss medium. Splodge a lot on the tile and on the photo, smooth it down (you can use a brayer, but I used my hands), and leave it overnight to dry.
Next, I added tissue paper across the middle and corners to give the piece some depth.
I also stamped onto tissue paper (Stampers Anonymous, Tim Holtz - "Memories") and embossed it. I then glued this over the tissue paper on the tile.
Next I added lumiere paints.
That finishes off the tile. :0) And here are some other pics of spray paint images, negatives (reversing the sprayed pieces onto card), and ideas for patterns for general MeSsY pLaY!