Crossing for beginners: carry to the byline, head up, and deliver an accurate cross into the space between the keeper and the defenders. Two runners attack it, one at the spot and one at the back post.
Set a start cone on the wing and a second cone near the byline to mark where the cross is delivered from. A winger carries between the cones, looks up, and crosses. Two attackers start centrally and time their runs, one to the penalty spot and one to the back post. No defenders at all to begin with. Rotate every repetition: crosser becomes a runner, a runner joins the wing. Work both wings so players cross with each foot. Only add a defender once the delivery is consistently reaching the target zone.
Most crossing drills assume a player can already cross. They start with an overlap, a beaten defender or a conditioned game, and the delivery itself is treated as something the player brings with them. This one assumes nothing, which is why there is no opposition in it at all.
The first thing to fix is when the head comes up. Young wingers look up as they strike the ball, by which point the decision has already been made for them. Looking up before reaching the byline means the delivery is aimed at runners rather than hoped in their direction, and it costs nothing except the habit.
The second is the target. The most useful cross goes into the space between the keeper and the defenders, close enough to goal that a keeper is tempted but not close enough that he can claim it. That zone is worth marking on the grass, because a winger who is aiming at a place delivers more consistently than one aiming at a person.
The third is that there must always be more than one runner. A single attacker in the box makes a good cross look like a bad one, because anything not delivered exactly to him is wasted. Two runners, one attacking the penalty spot and one holding the back post, means a delivery anywhere across the face has a chance of finding somebody.
Rotate every repetition so the same player does not spend the session crossing, and work both wings so crosses are struck with each foot.
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.