Finish an air ball first time. Read the flight early, get into line, lock the ankle, and strike through the middle of the ball with the laces, keeping the volley down and on target.
A server lofts or crosses balls into the box at varying heights; the striker finishes first time on the volley or half-volley. Start with half-volleys off the bounce, then progress to full volleys out of the air. Keep the strike down and on target. Serve from both sides and rotate.
Volleys are missed high, almost always, and almost always for the same reason: the striker gets underneath the ball. Everything in this drill is arranged to stop that happening, and coaching the leg swing without fixing the body position underneath it changes nothing.
The first requirement is reading the flight early enough to get into the line of the ball rather than reaching across for it. A player who arrives late is forced to lean back to reach, and leaning back lifts the contact point below the centre of the ball, which is what sends it over the bar. Almost every ballooned volley is a positioning error being blamed on technique.
The second is the locked ankle. A volley gives the leg very little time and no ground contact to push against, so the power has to come from a rigid foot acting as one solid surface. A loose ankle at the moment of impact absorbs the pace of an incoming ball rather than redirecting it, which is why some volleys come off soft despite a full swing.
The third is contact point, and it is the one that separates the two versions. Struck through the middle or slightly above it, the ball stays down. Struck below the middle, it climbs. The half-volley, taken just after the bounce, is easier to keep down for exactly this reason and is worth teaching first.
Head over the ball, eyes down at the moment of contact, and follow through towards the goal rather than up into the air.
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.