I've been in love with Sashiko, the Japanese embroidery technique for a while. While traveling in Japan this Spring I went to Tokyo Hands, this fantastic department store in the Shibuya neighborhood in Tokyo, which has a lot of nice craft supplies. I bought a Sashiko kit for coasters. I couldn't read any of the instructions, but the technical drawings were so clear that I was able to do the stitches in the right order. It's a very fun process, you follow a path and don't need to cut the thread. I added chambray as the back.
To sew the back I found this tutorial helpful.