This trick is the opposite of Waterfall.
It`s one of the easiest tricks with three balls but it could be a bit confusing in the beginning.
Start with Your arms crossed with two balls in the upper hand.
Toss the first ball from the lower hand.
Recross hands and cross them again and catch the ball in the same hand (now upper hand).
Now toss another ball from the lower hand and catch it in the upper hand (keep hands in their position).
Now You are in starting position with changed sides.