Given my current position, I don't have a comparative advantage in reducing existential risk. So my strategy is (will be? akrasia...) to donate my time to the cause indirectly through money.
When it comes to my future day job, I'm pretty sure where to spend my marginal time: economic growth. Bringing growth to the non-western world brings more potential minds to work on the problems while increasing growth in general makes it cheaper, relatively speaking, not only to do the research that needs to be done, but also for people like me donate to the cause.
I suggest this basic plan for anyone who doesn't have a comparative advantage in working the problems involved in reducing existential risk: Go to your own field and do research that enables work on these problems. In economics, I am suggesting this is growth.
Also see rwallace's post - your babies can do the work you couldn't!
When it comes to my future day job
why not start a company and aim to make loads and loads of money?
See: this
I've been talking to a variety of people about this recently, and it was suggested that people (including myself) might benefit from a LessWrong discussion on the topic. I've been thinking about it on my own for a year, which took me through Neuroscience, Computer Science, and International Security Policy. I'm hoping and finding that through discussion, a much greater variety of options can be proposed and considered, and those with particular experience or observations can have others benefit from their knowledge. I've been very happy to find there are a number of people seriously working towards this already (still far fewer than we might need), and their deliberations and learning would be particularly valuable.
This is primarily about careers and other long term focused efforts (academic research and writing on the side, etc), not smaller incremental tools such as motivation and akrasia discussions. Where you should be applying your efforts, now how (much). Unless there's a lot of interest, it might also be good to otherwise avoid discussions on self-improvement in general and how to best realize these long term concerns, bringing those up elsewhere or in a seperate post.
A few initial thoughts: