Just thought I'd share another drill. It's from this past month's Green Cord curriculum.
The patiente stands in terza. The agente makes strikes to the patiente, who defends against them primarily with the off-hand, unless it makes super-good sense to defend them with the sword.
For added complexity:
The agente can change targets from high to low (or vice versa). This will test both players: the patiente must be able to defend both high and low lines (simple if their position is good) and the agente learns to time their strikes and their order appropriately. The agente should also look for gaps that form in the patiente's defense as well as undefended lines (eg. the off-hand is too low to defend the face.