Combine at one touch and finish first time. Play each pass firm and accurate, time the third-man run behind the line, and sweep the finish first time without breaking the rhythm.
Set the stations with cones. Play a one-touch combination toward goal: set it off, a first-time lay-off, a first-time through ball, and a third-man runner finishes first time, keeper in goal. Insist on one touch throughout, and time the run so the finisher arrives as the through ball is played. Rotate the roles and run it from both sides.
One touch is a rhythm, and a single control touch breaks it for everybody, not just the player who took it. The third-man runner times his movement to a tempo that has just changed, the defence gets the half second it needed, and the sequence collapses. That fragility is exactly why the exercise is worth running: it forces a standard of passing that ordinary drills tolerate breaking.
The standard is weight and accuracy on every ball, not just the final one. A pass slightly behind the receiver at one touch is unplayable, whereas at two touches it is merely untidy. Players discover quickly that the difficulty is not in their own touch but in what their pass does to the next person, which is a genuinely useful realisation.
Lay-offs into the path rather than to feet are what keep the ball moving forwards. A set played straight back at a running player forces him to check, and checking is the same thing as taking a touch. The lay-off should be angled ahead of him.
The third-man run has to start as the first pass is played, not as the lay-off arrives. In a one-touch sequence there is no time to react to what has already happened; the run is a prediction.
Worth being clear about the limits. This is a rhythm and technique exercise with no defenders and no decisions in it, so it should not be mistaken for combination play under pressure. It builds the quality of pass that makes real combinations possible, and it belongs before an opposed exercise rather than instead of one.
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.