The training plan for a U18 youngster player should not be a standalone plan.
Instead, it should be a early stage of the whole career plan for the player.
The whole plan for a player will be heavily dependent on his skill potential and estimated height.
In most cases, the plan should majorly follow the skill potential distribution, and slightly adjust based on the height and position.
Considering the teens are growing fast, and their future position may change, especially for those forwards, it would be a safe option to train common skills for all his possible position to a medium level.
For a player with more certain position, we may train his skills to a higher level.
For example, a tall player would be likely to play center in the future.
He will definitely need toughness, rebounding, contesting shots, and possibly some close-range shots.
Then we may safely train these skills to like 10.
Similarly, for a short player that will become a point/shooting guard, he will need speed, contesting shot, offense skills and possibly some accuracy skills.
Train these skills to 10 will be a safe option.
However, for players with estimated height around 200~208.
He might be either center, forward, or guards.
We may train his Athletic skills to some extent, but better not exceed 6 to keep the flexibility until his height and future position become more certain.
On the other hand, everyone will need contesting shots, it would be a good option until 10.
Training the offense skill till 6 may also be a good choice.
To sum up, plan your players final skill, train the skills he will definitely need in the early years but keep flexibility for adjustment.
Regarding the improvement jump, the jumping player immediately gain a large amount of training points to improve his skills at the cost of losing some of his maximum potential.
In other words, sacrificing the future for the present.
To maximize the benefit, there are two main considerations.
The first and the most important one is the benefit the player can bring to the team.
After jumping, would he be eligible to play on the main team?
If not, it would be better to train him more with high potential.
And the second consideration is the time, the best time for jumping is right after the player sign a cheap and long contract.
In that way, the team could have a skillful player on team with low salary for several years.
Instead, it should be a early stage of the whole career plan for the player.
The whole plan for a player will be heavily dependent on his skill potential and estimated height.
In most cases, the plan should majorly follow the skill potential distribution, and slightly adjust based on the height and position.
Considering the teens are growing fast, and their future position may change, especially for those forwards, it would be a safe option to train common skills for all his possible position to a medium level.
For a player with more certain position, we may train his skills to a higher level.
For example, a tall player would be likely to play center in the future.
He will definitely need toughness, rebounding, contesting shots, and possibly some close-range shots.
Then we may safely train these skills to like 10.
Similarly, for a short player that will become a point/shooting guard, he will need speed, contesting shot, offense skills and possibly some accuracy skills.
Train these skills to 10 will be a safe option.
However, for players with estimated height around 200~208.
He might be either center, forward, or guards.
We may train his Athletic skills to some extent, but better not exceed 6 to keep the flexibility until his height and future position become more certain.
On the other hand, everyone will need contesting shots, it would be a good option until 10.
Training the offense skill till 6 may also be a good choice.
To sum up, plan your players final skill, train the skills he will definitely need in the early years but keep flexibility for adjustment.
Regarding the improvement jump, the jumping player immediately gain a large amount of training points to improve his skills at the cost of losing some of his maximum potential.
In other words, sacrificing the future for the present.
To maximize the benefit, there are two main considerations.
The first and the most important one is the benefit the player can bring to the team.
After jumping, would he be eligible to play on the main team?
If not, it would be better to train him more with high potential.
And the second consideration is the time, the best time for jumping is right after the player sign a cheap and long contract.
In that way, the team could have a skillful player on team with low salary for several years.