This is a brilliantly simple & trick involving Fork Catches & the Fork/Palm Stack that has a great stop-start rhythm to it. Unlike many juggling patterns where at the very least one thing is on the move at any one time, the Twist allows you to come to a complete halt. The trick is quite easy to learn because you can take the time to adjust your fingers & roll the balls about in your hands during the pauses to get the positioning right before making any throws.
Now with three balls, juggle a cascade, throw & stop so that you are holding one ball in one hand & two balls in a Fork/Palm Stack in the other. From here you are going to throw the two balls in the fork/palm stack simultaneously, the other ball DOESN'T MOVE. The ball on the bottom of the stack will be caught on the other side in a fork & the ball on top will be caught by the same hand. When you complete the move the position of the balls has swapped sides from holding two in the left (for example) to holding two in the right.
Keep your hands close together with your fingers pointing out in front of you, both hands need to face palm down & both need to have the ring & index fingers extended into forks. Obviously one hand won't have a choice because it is holding two balls. Throw the two balls in one hand by lifting & twisting your forearm to the outside (Clockwise with the right hand & anticlockwise with the left), the lift makes the balls rise when you release & the twist will separate them. Catch the bottom ball in a fork catch on top of your opposite hand & Claw Catch the top ball with the same hand. That is one repetition of the trick, carry on by twisting from the other side & stopping & so on.
Also try catching the top ball palm up instead of Clawing it palm down. The flicking from palm up to palm down between the two hands creates a nice effect. Another simple variation is to turn your arms in so that they are parallel with your chest. Throw & fork catch the lower ball from the stack as normal, but flick the top ball out to the side then swing inwards & down with the same arm & make a Penguin Catch.