7 Places NOT to waste your energy:

We can't waste valuable energy on mindless activities while putting off what matters most for later.

In business, wasting energy means working on low-value tasks, and thinking busywork is the same as productivity.

Instead of watching the clock, energy management can be used instead of time management. Our positive mood is high in the morning, dips in the afternoon, and rises again in the evening. We can use this information to our advantage and plan for our high-priority work when our mood...

You may have found that at certain times in the day you have more energy to complete certain tasks. Or maybe you just feel more motivated to do it. 

So pay attention to when those times are and manage the tasks you complete around your energy, not your time.