My personal rule is that if you aren’t quite certain that a certain action will be good for you and the world, you shouldn’t do it. Do nothing, which is likely to be pleasant and unlikely to hurt anyone. Few atrocities have been committed by people lying in bed, whereas the urge to Do Something has led to serious catastrophe. Productivity is extremely dangerous.
At every moment, you are hurtling through space at around 70,000 miles per hour, while also rotating along with the rest of the Earth’s surface at a speed of a thousand miles per hour. You’re filling your lungs with air, over and over, and as long as you’ve eaten recently, blood is taking nutrition to every part of your body and creating it anew. Even if you’re sleeping, your mind is always occupied with something. Do you really, actually, need to be doing any more than this?