One of the many fun experiments you can conduct with calligraphy is using this double pencil described in my last entry....you can change it to two ballpoints, or two marker-tips, or two different colors.
Now make some doodles that you feel like making, or even try a one-letter image, like a lower case "a", not letting the pen-angle change (see my last entry) as you "make your marks". Feel free to go back afterwards with a single implement to correct things: bring loose ends together as you want them. (Nobody is perfect the first time.)
Now the fun part is filling in the spaces you that you have made with your calligraphy: you can go to another media altogether, like a colored pencil or a marker, or a ball point, or watercolor, and you can make stripes, or polka dots, or wiggly lines or solid color, or whatever your heart desires, fear not! If you feel like attacking a whole word, or your name, or the name of a loved one, or a logo, you'll have even more fun.