Understanding the rules to games is the single biggest skill to develop, if you aim is to put up a big score. Having a strategy and knowing where the points are makes a huge difference. I find watching tournament videos the best way to learn strategy, might not be as in depth as say bowens papa tutorial. However watching how players approach a game in an actual comp setting is very informative. You soon realise that it's not how long you keep the ball alive or how many shots you make, it the quality of the shots.
Personally my biggest focus at the moment is ball control in multiball, resisting the urge to bash away, and keep at least one or two ball cradled up.