The first Christmas song that came to mind was Frosty the snowman. Applique a snowman with snowflake fabric as the background. Next, I thought of Jingle Bells. Applique a sleigh with jingle bells. Also, I'm Dreaming of a White Christmas. Use white fabric for the snow and applique a house with snow on the roof and a Christmas tree in the window. For a bit harder song, you could make a pretty Star block...to represent..We 3 Kings...there is a verse with Star of wonder, Star of Light.... This sounds like such a fun challenge. Let us know what you decide.