Your triangles can be as long or short as you like, but remember that the longer the paper, the thicker the bead will be. The end of your cut paper can come to a point or be cut straight. For uniform beads with a flat edge, try this printable template by Kate Pullen. This is ideal for stamped beads.
To make a cocoon-shaped bead, cut the angles unevenly, making one side a sharp angle, and the other more of a straight line. Experiment with cutting techniques to see what kinds of beads happen with varied angles.
Next, let's roll the paper.