Make a list of all the projects you could undertake, then use Fermi calculations to estimate the costs and benefits of each on various axes (time, money, status...), with time discounting. Combine the axes into one measure of how much you'd profit from doing each project. Then actually use the numbers to decide what to work on next.
You might also intuitively guess the profit from each task and take a weighted average of that and the more analytical calculations, because system I often outperforms system II.
I'm currently in the middle of this; so far the top items match my intuitions (e.g. go do more CoZE), so I'm not benefitting much from the analysis. Part of my reason for creating this thread is to gather more ideas for things to do and to get other people to help me research how worthwhile possible projects are.
What is CoZE?
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.