Other Tutorials:

CissyandtheMan (demonstration)

     The Shuffle-Switch is a variation of Columns where you do a rapid double-pass of the outside balls between hands, before tossing them up. This is one of the more difficult variations, with the high speed "shuffle-switch" dramatically changing the normal timing of  the Columns pattern.

    To learn the trick, it is best to first concentrate on the double pass by itself. In order to prevent the balls from colliding into each other,  you will need to slightly change the height of each throw, with one hand lower than the other.
    You will need to be comfortable enough with this to do it without looking, since your focus will be directed towards maintaining the Columns pattern, with the passes happening on the very edge of your peripheral vision. Once you have this step mastered, you can simply add one or two "shuffles" into a normal Columns run, eventually working your way up to doing a constant Shuffle-Switch. The shuffle move itself is not limited to this particular trick, and can in fact be incorporated into other patterns such as the Shower (thus becoming a variant of the High-Low Shower).