Using only two styling tools, the volume styler and an elastic band. The volume styler adds texture, volume and a perception of thickness to your ponytail, but since it needs to be hidden, you need the elastic band.
Here are the steps of how to use the Volume Styler:
Gather all of your hair into a ponytail at the back of your head.
Put the Volume Styler just below your ponytail.
Wrap the elastic band around the volume styler while tieing your ponytail.
Spread the ponytail over the Volume Styler, so that you take maximum advantage of it, but still hide it.