I just finished reading The 80/20 Way by Richard Koch. This book talks about the Pareto Principle, which says that 20 percent of our actions give us 80 percent of our results.
This is important for flow because there are certain things that give us much more flow experiences than many other things. If we are able to narrow down those things and be able to perfect them, we can more easily expand flow in our lives.
For me, it is about learning and mastering the process for getting into flow, and then being able to easily apply it to anything else.