Deliver an inswinging corner to the far post and attack it with a timed run. Whip it beyond the near-post players, time the far-post run to arrive late, and head it down and goalward.
From a corner, whip an inswinger beyond the near post to the far post, where an attacker times a run to head it. Deliver with pace and bend so it drags the keeper and finds the space behind the front markers. The far-post runner starts wide and attacks late. Rotate taker, attacker, and keeper, and add near-post and spot runners as decoys.
Goalkeepers position themselves to protect the space they can actually reach, which for most is the six-yard box and the near half of the goal. That decision is sensible and it creates the opening this routine attacks: the far post is the part of the box a keeper is least able to defend and least willing to commit to.
An inswinging delivery makes the problem worse for him. A ball bending towards goal pulls a keeper forward, because every instinct says come and claim it, and a keeper who takes one step off his line and does not get there has vacated the goal entirely. Bent beyond the near-post crowd, the same ball arrives in the one area where nobody is favourite to win it.
The run is what makes it work, and starting position is the detail coaches miss. A far-post runner who begins at the far post is marked and static. One who starts wide, almost outside the box, and attacks the space late is arriving at pace from an angle his marker cannot track while also watching the ball. That is the same principle as the near-post flick, applied at the other end of the six-yard box.
On the contact, heading it down and back across goal is worth insisting on. A downward header from the far post travels towards the middle of the goal and away from a keeper whose weight has already shifted forwards, and it is far harder to save than a header struck flat.
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.