Harrison's Hang is a three ball
pattern established by Danny Harrison. It can almost be thought of as
Penman's Pandemonium grafted onto a 441 base, though this description isn't
entirely accurate. You will therefore want to be very comfortable with both
of these tricks before attempting Harrison's Hang.
To begin learning Harrison's Hang, start with two balls in your dominant hand and one ball in your non-dominant hand. Shift your dominant hand over to the non-dominant side of your body, and then raise your non-dominant hand such that it is positioned over your dominant hand. Make a throw from your dominant hand toward the center of your body while simultaneously swinging your non-dominant hand around in a three-quarter circle such that it passes inside of, under, and then outside of the ball your dominant hand just threw. As that ball descends and as your non-dominant hand completes its partial circle you are going to move your dominant hand directly underneath your non-dominant hand, and then make a vertical pass from your dominant hand to your non-dominant hand, clearing space for your dominant hand to catch the first ball it threw. At the same time you will make a vertical throw from your non-dominant hand (with your palm facing down), clearing space for your non-dominant hand to catch the vertical pass. Your non-dominant hand will then catch its vertical throw.
As shown, practice this on both sides. You have basically performed one full cycle of Harrison's Hang. To connect two cycles together (i.e. to connect both sides of the pattern) you are going to take your non-dominant hand, which just caught the vertical pass, and cross it over to the dominant side of your body; you will then make a throw from your non-dominant hand toward the center of your body. At the same time you will raise your dominant hand and begin moving it in the same three-quarter circle that your non-dominant hand did at the very beginning—rotating inside of, under, and then outside of the ball thrown by your non-dominant hand. Your non-dominant hand will then catch the ball it threw.
Notice that the last throw and its accompanying arm flourish are a mirror image of what you did at the beginning; to continue that pattern simply make another vertical pass (from your non-dominant hand to your dominant hand this time) and proceed from there. Harrison's Hang is a fairly easy yet fun pattern to juggle, especially if you enjoy vertical passes.