I am totally anal-retentive about using coasters in my home.  So when I was looking for ideas for the kids to make Christmas gifts for family in 2011, I was drawn to this simple craft idea on Pinterest.  These coasters are made from inexpensive bathroom tiles, scrapbook paper, mod podge, and an acrylic sealing spray.  I had the kids pick out papers for their grandparents and aunts/uncles and they made sets of coasters for each of the families.  These three coasters are ones that they made for our home.

I found the directions here. The only difference was that I used thin rolled cork on the backs of them, and I had the kids write their names and the year on the cork backs.