I agree with everyone when saying train your SF like you run your team. I good SF can be the make or break player on a team, and will basically determine match-ups against people running outside or inside strategies. On defense, an SF is pretty easy to build, as high of OD and ID as you can get. Its on Offense where how you build your SF really matters his play style. If you run LI build a SF with higher IS, if you run Motion then build his outside shooting. It's personal preference at that point, and more so how he fits into your strategy. I like to have a balanced SF who can perform in any offense but that's my preference. The most important thing with SF is Defensive versatility cause one game he might be guarding an PF type player, and another game could be guarding a SG type player. SF is also the only position that changes from guarding the perimeter to the key when switching between 2-3 and 3-2 zone.