The Follow is a three ball
pattern in which one ball is carried behind another, duplicating its arc,
and then switches positions for the next cycle. This trick is one of the
many 423 variations and as such it's a fairly easy pattern to learn, though
the carry might take some practice.
To begin learning the Follow, start with one ball in each hand. Cross your non-dominant hand over to the dominant side of your body and position it right above your dominant hand. Make a throw from your non-dominant hand back toward the non-dominant side of your body and then, as you are making this throw, begin following the thrown ball with the ball in your dominant hand, continuing as the thrown ball peaks and begins to descend. Catch the thrown ball with your non-dominant hand, making sure to follow its descent with your dominant hand; the held ball should end up positioned right above the caught ball, similar to the way you started (with hands reversed).
As shown, practice this on both sides. You will want to be comfortable enough such that you can switch directions quickly and smoothly. To add in the third ball, start with two balls in your non-dominant hand and one ball in your dominant hand. Position your non-dominant hand above your dominant hand and then throw a ball from your non-dominant hand back toward the non-dominant side of your body. Follow this ball with your dominant hand, just like you practiced in the first step. As the thrown ball descends you are going to throw the other ball in your non-dominant hand as an under-the-arm throw, crossing it over to the dominant side of your body beforehand. This will clear space for your non-dominant hand to catch the first ball it threw (the one being followed). You will then throw the ball in your dominant hand—which should have finished its carry and now be positioned above your non-dominant hand—back over to the dominant side of your body and catch the under-the-arm throw with your now empty dominant hand. Your dominant hand will then catch the last ball.
Once again, practice this on both sides. Notice how the last throw is basically a mirror image of the first throw—to continue juggling the pattern simply follow that last ball with your non-dominant hand and do the under-the-arm throw with your dominant hand, repeating the cycle with hands reversed. The Follow is an easy but fairly unique three ball trick, which is a great combination for beginners.