How do you know what matters most?
In order to do what matters most right now, you need to first know what matters most. That is not always obvious.
I use a simple test to see if I've got it. I ask, are "should" and "want" and "can" aligned for this action? If they are, this is clearly a valuable step to take, and there is no evidence that something else is more important. If they aren't, it's worth a few more minutes to align them.
You need all three in alignment, "should" and "want," and "can," if you are to be sure. If any one is off, that's evidence there is a flaw in your thinking or a competing value that may be more important.
For example, you may conclude that you should write a report right now. However, it would take at least 90 minutes, and you have a hard stop in 20. You can't literally do it, and as a result, you will likely feel some resistance to starting. Realizing you can't do it can spur you to change your goal to outline the report in 20 minutes, so "should," "want," and "can" fall into alignment.
Or suppose someone puts a 1000 calorie dessert in front of you, and you want it, but you don't believe you should eat it. Knowing you shouldn't do it can spur you to get up and walk away so you are out of the range of temptation, and with no conflict between "should" and "want" and "can."
Honestly, I don't think it's hard to test whether you know what matters most at the moment. The real challenge is threefold:
a) How do you remember to verify that you've got all three aligned before you act?
If you don't pause to consider that, that 1000-calorie dessert will be in your tummy.
b) If they're not aligned, how do you figure out what does matter most quickly?
When the obvious task (write the report) is not quite right, you don't want to spend all your time figuring out a better approach. Planning should only take about 5% of the time.
c) When there are two incompatible options, how do you choose one and then align your feelings around it?
For example, suppose you are under a deadline to do some detailed financial work, but you are wildly distracted, wanting to write a letter to the editor instead. If either task is to be done, it needs to be done today. You don't have time to do both. It's either-or.
These situations are less frequent than people think, because most apparent conflicts are resolved after a few minutes of thinking. But they are common.
In these cases, I don't recommend you gird your loins and force yourself to do one or the other. Nor do I recommend that you wait until all three elements of motivation align.
Rather, I recommend you learn to address the conflict in action, right now. That means take both options seriously, make a rational choice between them, reinforce the positive motivation for that choice, plus dispel the negative motivation pulling you away from it. And again, you need to be able to do all that quickly.
These are all learnable skills. A particular kind of skill.
In case you didn't notice, "should," "want," and "can" are a shorthand for thought, feeling, and ability. When you have total objectivity about your own thoughts, feelings, and abilities, you can always find a step toward your top priority, a step that is clearcut, doable, and important.
That is the skill of self-management. That is the skill that enables you figure out what matters most. And do it.
Because if you align "should" and "want" and "can," you will also be propelled into action.