Finish with placement, not power. Set the ball, pick a corner, and side-foot it accurately past the keeper with a still head and an open body.
A feeder plays the striker in, who takes a touch to set the ball and side-foots a placed finish into the corner past the keeper. Emphasise picking the corner early, opening the body, keeping the head still, and using the inside of the foot for accuracy over power. Vary the corner and the angle. Rotate the roles.
Far more clear chances are missed by hitting them too hard than by hitting them too softly, and the placement finish exists to break that habit. Inside the box, the keeper is close and set, so the only parts of the goal genuinely unavailable to him are the corners. Power does not open those up. Accuracy does.
The side-foot is the correct tool because it is the most repeatable surface on the foot. A player can pass a ball into a one-yard target from twelve yards all day, and a finish from that range is exactly the same action performed under pressure. Framing it as a pass rather than a shot changes what players do with it, and it is worth saying in those words.
The decision comes first, though. Picking the corner before the ball arrives means the body can be set for it. Picking it during the strike produces the shot that goes straight down the middle, because the player has effectively aimed at both corners and hit neither.
Two body details do most of the work. A still head keeps the whole strike stable, since the eyes coming up early drags the shoulders and the ball with them. And leaning back lifts it. Standing over the ball with the chest forward keeps a side-foot finish low, which matters because a keeper's feet are slower than his hands.
The first touch should set the ball into a striking position rather than simply stopping it. A finish taken from a ball that is under the feet is far harder than one taken from a ball half a yard in front.
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.