In the square drill, three players stand on three corners of a square. One and Three hold discs. One Player with a disc throws to the player without a disc, who receives at the open corner.
Third player cuts for the open corner immediately, and receives from the other dude.
You get the idea. This is a very fast moving drill. Unlike a give and go you actually receive the disc straight away, from another player, quicker than a real give'n'go. Note that you will automatically alternate backhand passes and forehand passes. You always pass to one player and receive from the other.