The drill starts with four players on the four perimeter spots as shown below.
Player 1 starts with the ball, passes to player 2 who swings to player three who swings to player four in the corner for a jumper. Player four gets his own rebound and as he is, 1-2-3 all rotate one position over to the right to cover the open spot left by four. When four gets the rebound he makes a good pass to 1 (who is now at the guard spot on the left side of the diagram). Four fills the empty wing spot. 1 passes to two, who passes to three, who then shoots from the corner. Three gets his rebound and everyone rotates.
I make sure to run the drill so that the shooter is taking shots from both sides and getting used to ripping the ball into his shot pocket from both angles.
I also like to use this drill as a competitve drill where teams race against each other or need to make X number of shots in X number of time. Gives the passes a little more zip and the shots a little more pressure.