Keep two first-time 1-2s sharp under traffic: inner players returning two balls in quick succession, and runners timing their arrival so the three balls never collide.
Mark a triangle of markers 5 metres a side, and around it a triangle of cones 16 metres a side on the same centre, each cone out beyond a marker. One player stands just outside each inner marker, and two players stand at every outer cone, the front one with a ball. All three front players go at once. Each takes it round the outside of his cone and plays a 1-2 with the inner player nearest him, runs on along the outside of the big triangle and plays a second 1-2 with the next inner player, takes a touch, and passes to the next outer cone. He follows his pass and joins that line. The players at the cones meet the balls outside their cones, take them round, and the next rep starts together. The inner players play everything first time: every rep, each one returns the ball from his own corner, then the ball coming along from the corner before.
Three balls at once changes the job of the inner players completely. With one ball they return a pass and wait. Here every inner player plays two 1-2s every rep, less than a second apart: first with the runner coming from his own corner, then with the runner coming along from the corner before. He returns the first ball, opens straight up, and the second is already on its way.
That makes this a scanning drill as much as a passing one. Before the first ball arrives the inner player has to know where the second runner is, or he will turn into the return and miss it. Coaches can hear the difference: the good groups talk, and the returns come back on the same beat every time.
For the runners the pattern is the same as with one ball. Take it round the outside of your cone, 1-2 with the nearest inner player, run on along the outside of the big triangle, 1-2 with the next one, take a touch, and pass to the next outer cone. Follow your pass and join that line. The difference is that all three lines go together, so leaving late means two balls arrive at one inner player at once and the rhythm collapses.
Nine players means two at every outer cone and three on the markers. It is a high tempo block: rotate the inner players every couple of minutes, and if the passing breaks down, drop to two balls before going back to three.
Save it to your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block. Or start from a blank pitch and build your own.