Create a lane 3-5m wide, and long as you like - place cones at intervals same distance as lane width. Line-up evenly behind (A & B), every player at (A) has a ball.
The basic rule to remember is (A) can only pass directly ahead, (B) can only pass laterally. Both players run diagonally after each pass, crossing over to the other line.
(A) has the ball, while (B) crosses over to (A)'s side to receive at cone (1)
When (B) catches they should leap and prepare their body to drive towards (2)
After passing, (A) runs diagonally to (2) to receive a lateral pass from (B)
Continue in this fashion with (A) passing ahead to (B) at (3), then (B) passing sideways to (A) at (4), and so on until all cones are visited
Remember, players cross-over after passing, then receive (B: down the line / A: laterally)
Once a pair have 6 passes, the next pair can begin with their own ball.
Once all players have been through, pause briefly, give all the balls to (B), then restart, this time (A) runs first, (B) passes ahead, (A) passes sideways.
Remain at the same end and work back the other way.
Progress/increase the challenge by widening the lane.