Create a free header from a corner with a blocking run. Screen the target's marker as he peels off, deliver into the space he runs into, and attack the ball unmarked to score.
From a corner, a teammate makes a blocking run across the target's marker as the target peels off to the space. The corner is delivered to the free man, who heads it at goal. Emphasise the timing of the block and the peel, and delivering into the space. Rotate the roles and vary the target area.
Screening at a corner sits right on the edge of what referees allow, and the difference between a legal block and a free kick against you is almost entirely about the hands. A player who takes up a position and stands still, letting a marker run into him, has done nothing wrong. A player who reaches out, grabs, or steps across at the last moment to make contact has committed a foul, and referees at every level are increasingly alert to it.
That distinction is worth teaching explicitly, because the routine is legitimate and effective when done properly, and a needless free kick throws away the whole set piece.
The mechanic borrows from basketball. Two attackers start close together. One holds his ground in the path of the other's marker, and the target peels away in the opposite direction. Because man-marking defenders are watching their man and the ball at the same time, a stationary body in the running lane is genuinely difficult to avoid, and the target arrives at the ball unmarked for a moment.
Timing is what makes or breaks it. The block has to be set as the target breaks, not before, because a blocker who takes up position early is simply standing next to a defender who has time to step around him. And the delivery has to go into the space the target is running into rather than to where he started, which means the taker needs the same cue as the runners.
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.