If you don't want to make the tassel out of card stock, you can make it out of embroidery floss. Make a 3-inch loop of string. Cut it on one side. Tie a small piece of string around the other side. That will form a loop. Put a long piece of string in that loop, then glue that piece to the top of the card stock graduation cap. Alternatively, you could use crepe paper. Roll it up, cut it, glue it to ribbon, and then tape that to the top of the cap. This is your DIY graduation gift, so you can use whatever supplies you want.