Andean Plying is a technique of winding yarn around your hand so you can ply from both ends. Spindlers are usually shown this method as a way of plying a spindle-full on itself. Traditionally, however, it's used to finish off the longer of two balls of yarn from spindles.
I have a pictorial of this published on ispindle.com. (Unfortunately, I made the videos with old-tech, and they don't seem to play anymore -- sigh.)
Recently a new Andean plying method has cropped up -- the Andean Plying Paperback method by Rosemary Knits.
Returning to the topic now, for details on splicing the end of the bracelet to the finished end of the first ball of yarn, I went back to the source -- Ed Franquemont (yes, he's Abby Franquemont's father! How cool is that :-) ).
Ed Franquemont was the first to transcribe the Andean Plying technique for the modern US spinner, stating in the Summer 1992 Spin-Off, p. 106, "this [(the end of the Andean ply winding)] she teases open and splices with the end from the emptied spindle to make a continuous, knotless, doubled strand that can be wound onto the ball." The technique is shown again in Summer 2007 Spin-Off and available online, in Spinning Basics: Andean Plying.
I'd note that Mr. Franquemont is describing this relative to the Andean practice of taking two full spindles and winding the strand from each into a 2-strand ball to then ply from. Abby Franquemont (Ed's daughter!) wrote a great piece showing this practice on Fiber Femmes, simply called, Plying.
Since Mr. Franquemont says the ends are teased open and then a continuous strand is made, I'd take to mean fluffing out the ends and rolling/spinning them together. I blogged about this in What is Spindle Splicing?
If you find that method isn't working for you, there are other splicing possibilities -- felted join (spit-join), Russian join (also available on YouTube), the overlap join, or the back join. Most of these are shown in relation to knitting yarns, but can easily be applied to the single strands and laid next to the continuous strand of your other ply.
Click for a list of all spindle posts on Ask The Bellwether. A few relevant favorites:
How do you avoid getting a purple finger with the Andean plying bracelet?
What is spindle splicing?
How do you make a strong join?
How can I combine two spindle-fulls into a larger skein?
So, how do you use Andean plying? Front of the hand, back of the hand, paperback? To combine the longer of a bobbin or spindle-full with the shorter, or to ply a spindle back on itself? What join do you use?
Questions or comments - post on the blog or contact me. Thanks!