Essentially it's this: in planning your day, identify the action that would make you feel fantastic to get done today. Do that first.
If you give it a shot, or already have experience with this, please let us know how it works for you.
I've sometimes done first "the thing I feel most nervous about." But that's such a negative way to code it. Even so, doing it makes me feel fantastic. I'm going to hang onto the "fantastic" label for this strategy.