I see these all over Flickr and they're so cute! They're sort of a little snack mat for a cup of coffee or tea and a few cookies or a little sandwich. They can be as simple or as complicated as your time and creativity allow! They could be pieced with a small version of a quilt block or appliqued or just scrappy pieced. If you need a little inspiration, go to Flickr and search "mug rugs".
We're going to do a super fast one. For this tutorial, I picked this cute mug that came with a flower arrangement. Then I found some fabric to match.