Groups of 3 players: 1 group on the foul line, 1 at 15 yds into outfield, and 1 30 yds into outfield.
Player 1 throws to 2.
Player 2 catches, turns and throws to 3.
Rotate every 10 throws.
This accomplishes several things at 1 time.
First- throwing and catching (obvious).
Third- fast hands
Four- turning and finding your target.