Lay two 4 1/2" long pieces of duct tape on your work surface. They can be different colors or the same.
Flip one piece over so it is sticky side up. Lay the second piece on top of that piece leaving approximately 1/4" of sticky at the top.
Decide which side you would like to be the outside of the tassel. In this instance it will be the polka dot. Lay the tape so the pattern you want on the outside is facing up. Fold the sticky edge of the other color tape over onto the outside piece of tape.
Carefully fringe the tape by making thin cuts with your scissors. Do not cut into or through the sticky.
Lay your pen with its end (not the point) on the sticky edge of the tape pieces.
Roll the tape around the top of the pen.
Once you have finished rolling the tassel all the way around you will need to seal it with a few small pieces of tape. Take a 2" piece of tape in one or both colors and cut it in half length-wise. Seal the bottom edge of the tassel with one piece of tape.
Place another piece of tape just below it.
You can seal the entire thing by placing a third thin strip around the bottom piece of tape.