Each group of 3 need a ball and a 20m playing square.
(B) leads along one side of the square and marks the kick from (A)
Represented by arrows marked "1"
(B) should mark as close to the cone as possible.
(B) turns to face the cone they came from, and gets back off the "mark". (C) leads down the edge of the square receive on the cone (B) was on
Arrows marked "2" in the diagram
(C) turns to face the cone they came from, and kicks to (A) who leads towards the (C) was on.
Arrows marked "3" in the diagram
Continue in this fashion around the square, concentrating on accuracy. After a while, call "change direction" and reverse the flow of play.
Progress by taking the cones further out so kicks are longer, however you may be constricted by space given there will be plenty of squares around the oval.