Balancing busy work with getting real work done

There are only so many hours in the day. We're all busy. So how should we spend our time? What's important? As a designer (or design manager) there are certain tasks that bring us a LOT more value for the time we put in than others. How do we figure out what they are, and what should we be spending time on? Note: this talk is not on a 2x2 prioritisation matrix.