This is a diagram to help illustrate how to Andean ply.  It is a means of plying from one yarn source.  It is most commonly used with spindle spinning, but can be used for wheel spinning as well. Start by winding the free end of the singles yarn onto the peg at the bottom.  Then follow the diagram and wrap the yarn from the spindle onto your plying tool.  When you have it all on your tool, keep track of the two ends of the yarn, and gently remove the peg at the top.  Don't lose that "ring" that was formed around the peg.  Now take the two ends of the yarn and attach them to your spindle, and proceed to ply.