Buy some good PG;)You cant improve your flow by any tactics. It depends mostly of passing skills of your players, especially PG and SG. Also handling is important for ofensive flow, I think
From the rules:OFFENSIVE FLOW- point guard weighted very heavily- shooting guard and small forward weighted mediumSo the rules don't mention anything about the PF or C having any impact, though I suppose it is always possible they have a small impact and the game designers just didn't think it worth mentioning.