Thank you BigT for this great initiative
I would like to add some things:
•If your player needs ballhandling and/or driving, the best option to train (this is my opinion/experience) it is 1vs1 SF/PF. Also if you're training a PG or a SG! This has the advantage that not only driving, ballhandling (about every 2 weeks) and jumpshot (4-5 weeks) will progress, but also his Inside shot (4-5 weeks). I myself prefer to play with guards that have their IS trained too (for exemple till 8).
•For the SF position their isn't really an ideal skillset for the U21, because the SF is the most difficult to train. I would say that if you're training a SF for the U21 team, you should make a decision between an outside SF or an inside SF. The decision often depends on the height of your player : <201 cm --> outside SF , >201 cm --> inside SF
Both types should require at least 10 OD and 10 ID, but if you're training an outside SF, you should be aiming more for his outside skills ( 10 JS , 8 JR) , if you want an inside SF this is a nice goal : 10 IS, 8 RB
•If you're draftee has a potential MVP or higher, I would advise to start with training the secondaries first till an acceptable level.
For guards : IS, ID till 8
for PF/ C: JS, OD, PA till 7-8
You don't have to be affraid that he won't reach the U21 anymore if you 'waste' a season of training. This isn't wasting, it's preparing for the NT. And probably, your player could be used as a SF when he's 21 years old.
• 19 year old draftees (potential 6 or higher) can also reach the U21 team, so think again before you put it up for sale or dismiss him.
If you have questions, don't hesitate, just ask ;)