Two opposing lines (1 & 2) are 4m apart, and the 4 cones on each are spaced about 2m apart. Give a ball to each (A)
(A)'s pass to one another
One (A) uses a chest pass (over), the other a bounce pass (under)
Next time (A)'s change who shoulder and bounce passes
The pattern for passing is then:-
Retain current direction but skip the player opposite - (A's to B's), (B's to C's) (C's to D's)
When it reaches (D)'s, they exchange passes like (A)'s - simultaneous chest and bounce passes
Then work back the other way (D's to C's), (C's to B's), (B's to A's)
Both players with the same letter should be passing simultaneously, so use peripheral vision to keep in sync.
Option call for a variation in pass each ball, e.g.:-
Ball 1: Shoulder pass
Ball 2: Overhead pass
After 2-3 minutes, bring the lines an extra 2-4 m out; repeat using shoulder passes.
Trickier for (A)'s and (D)'s!