Split into groups of 7, with 5 balls per group. Two players stand 1 metre apart in front of a line of 5 players about 1-2 metres away. If you don't have enough balls to cover everyone, send half the squad off for some fitness work.
Player (C) handballs to (A), who quickly feeds sideways to (B), who handballs back to (C)
All players use voice so (B) knows where to return the handball.
Just before (C)'s handball reaches (A), (D) fires their handball to (A). Having just handballed, (A) must react quickly to take this ball and again gives to (B) who handballs back to (D)
The key is to make it challenging for (A). It's no good if the next ball arrives while (A) is still holding the last ball, nor is waiting for the next ball to arrive of much use.
The exercise continues in this manner, with (E) (F) and (G) firing their handballs to (A) in quick succussion.
After (A) receives three handballs from each of (C) to (G), stop and change directions. This means (B) receives the handballs from (G) to (C) in that order. (B) gives to (A) who returns to (G) through to (C).
After three handballs from each of (G) to (C), swap the positions of (A) and (B) and repeat steps 1-4 above.
This gives players practice using both hands.
Once (A) and (B) complete the 4 variations of 15 handballs, swap them for two players out of (C) to (G) and repeat steps 1-5 above.