David Aiken, The Checkerboard Guy, demonstrates the Inside Single Cup Flip with shaker cups.
The following article first appeared in the Sep/Oct 2005 issue of JUGGLE magazine, the official publication of the International Jugglers' Association. The publisher has kindly given permission to reproduce it here.
Hold the white cup in your left hand. Your right hand holds the black cup. The striped cup nestles in the black cup.
Turn your right wrist counterclockwise, describing an arc to the inside, so the striped cup flies out of the black cup and over to the white cup. The striped cup rotates once in a counterclockwise direction within the wall plane as it flies up and over to the white cup. (see photo)
With your left hand catch the striped cup in the white cup. (see photo)
An inside flip for the left hand is clockwise. Turn your wrist in a clockwise direction so the striped cup slides out of the white cup and flies over to the black cup in your right hand. The striped cup makes another single-spin rotation within the wall plane before the striped cup lands in the black cup. This time, however, the striped cup spins in a clockwise direction as you see it.
That's it. You have completed both halves of this move. The white cup never leaves your left hand. The black cup never leaves your right hand. The striped cup flies back and forth between the other two cups. Squint your eyes and you can imagine the striped cup describing the flight path of a Reverse-Cascade.