You need at least one great shooter and a good supporting cast or 2-3 decent shooters with, again, a good supporting cast. Its best you have an SG with good range and JS and an SF with slightly less range but similar JS. Your PG needs to be a good passer but so do all other players since you're trying to move the ball around for a good shot. As mentioned before it helps a lot if one of your big men also has decent JS and okay range. In which case your other big guy could be a rebounding/passing machine and really maximize the offence.
You can try out other variations and see what suits your team, but what I gave is the general idea. You might, for example, try having a scoring PG and a driving SF, etc. Also, the skill levels your players require will depend on how good the opposing defences are. Hope that helped.