Get yourself some poly yarn, some 5/16" orthodontic rubber bands (ebay), and hemostats.
Then, grab your leader with the hemostats.
And slide the rubber band onto your leader.
Let go with the hemostats. You are done with them.
Cut off a piece as large as you would like for your indicator.
Put your yarn through the loop in your leader.
Slide the rubber band up close to the yarn to fix the yarn in place.
Grease the crap out of the yarn, and get some fish!