Shape a Bi-Cone bead. In this sample the bead was formed using the Bi-cone bead roller, the largest size. To swirl color, place some contrasting color over the bead from point to point. Set it in the base of the bead roller and travel it to the far end. Pick the bead up and without turning it place it back in the base (at the end) and re-roll it in the same direction. Repeat this until you like the design on the bead.
Set the bead point down on your work surface. Place a flat sheet of Plexiglas or a tube bead roller top over the bead. A Tube bead roller top would work nicely for this. Herinafter the reference will be "tool".
Rotate the tool over the bead in a circular motion. Imagine the point of the bead against the work surface as an axis, that will stay turning in the same spot. The things that will affect the shape the bead takes on are downward pressure, tilt of the tool, and how wide the circular motion. If you've never done this, practice a bit. It is a "feel" thing, but like riding a bike. Once you have it, it will stay with you.
Pierce through your lentil shape. If the tool is placed over the bead towards one edge, the bead can be pierced from the side while under the tool to prevent finger prints.