Hello
I'm currently training a small forward (3rd season now), and I've researched it quite a bit and the conclusions are:
You'd want to train 1vs1 forwards until your handling is at least 17, this will give you a high level of handling and driving that will give you a nice amount of elastic effect for outside defense and jumpshot. And this should work for every type of small forward you'd want, but then you have to think about how you want the end skills to look like and what type of small forward you'd want and tailor the training for him.
For a more balanced I would say training Jumpshot forwards until JS reaches around 16-17 and then move into inside shot until 18-19. From here on you'd want to train both defenses (ID and OD) until their desired level what I would consider a balanced SF would have at least 17 in both defenses but depending on the goal and the potential of the players you might want to continue until 20.
To get to this point, it will take something like 8 seasons to achieve. From here on depending if you want to have the player on a national team or not you might need/want to continue training him and rounding up the remaining skills (passing, range, rebound and shot block)
If you'd like to discuss this more we can chat up some more details and have this be less generic.