Train the first touch that sets up a strike, under a spatial constraint. The ball must be controlled and struck without leaving a three metre box, so the touch has to be precise rather than merely adequate.
Mark a small box of four poles roughly three metres square, about nineteen metres from goal, and put the finisher inside it. Two servers stand on opposite flanks, well apart. They feed alternately into the box; the finisher takes one touch to control, keeping the ball inside the poles, and strikes with the second. Do not let the ball or the player leave the box before the shot. Change the finisher every two minutes and serve to both feet.
Shooting drills almost always allow the shooter to prepare the ball wherever he likes. A serve comes in, the player takes a touch to put it exactly where he wants it, and strikes. He gets very good at hitting a ball that has been placed perfectly, which happens rarely in a match.
The box of poles removes the preparation. Three metres square is enough room to control and swing, and not enough to push the ball out into the spot that feels right. The first touch therefore has to be genuinely accurate rather than roughly in the right area, which is a much harder standard and the one the game applies.
The simplicity is deliberate and worth keeping. Four players, four poles, a goal and a keeper. There is no pattern to remember, no rotation to manage, and no combination to get right first. Everything that could distract from the two touches has been stripped out, which makes it one of the few finishing exercises where a coach can watch the technique properly and correct it in real time.
Serving from opposite flanks is the detail that stops it becoming one-sided. A ball arriving from the left and a ball arriving from the right require opposite turns and opposite controlling surfaces, and a player left to his preference will take every one on the same foot. Alternating the side, without warning, is what makes the weaker turn happen at all.
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.