I have a very dear friend who collects, of all things, robots. I had an idea for a craft, to make a set of robot coasters. I know she will be absolutely thrilled.
4 4"x4" tiles
Whatever you're using as a design for the coaster
Spray clear coat
Something for the bottom side so they don't scratch the table surface
Apply your decoration (in my case pictures of robots) to the tiles with the spray adhesive and let dry.
Apply several coats of clear spray such as verathane.
Then apply the backing.
I cannot wait to see her reaction when she gets these in the mail.