I think raising the sanity waterline is the most important thing we can do, and we do too little of it because our discussions tend to happen amongst ourselves, i.e. with people who are far from that waterline.

Any attempt to educate people, including the attempt to educate them about rationality, should focus on teens, or where possible on children, in order to create maximum impact. HPMOR does that to some degree, but Less Wrong usually presupposes cognitive skills that the very people who'd benefit most from rationality do not possess. It is very much in-group discussion. If "refining the art of human rationality" is our goal, we should be doing a lot more outreach and a lot more production of very accessible rationality materials. Simplified versions of the sequences, with more pictures and more happiness. CC licensed leaflets and posters. Classroom materials. Videos (compare the SciShow video on Bayes' Theorem), because that's how many curious young minds get their extracurricular knowledge these days.

In fact, if we crowdfunded somebody with education materials production experience to do that (or better yet, crowdfund two or three and let them compete for the next round), I'd contribute significantly.