The Ferrett isn't an official member of the Rationalist Diaspora, but he's been blogging for longer than LessWrong has existed and often has useful insights that align with what the LessWrong community likes to talk and think about, and when I find one, I link to it. The advice in here might very well be of the "it seems obvious once you've read it" kind, but I think it's still useful - he's learned a lot of things about relationships the hard way, and when you get the chance, it's better to learn from other people's experience so you can avoid having to learn things the hard way too.

A short excerpt:

Twenty-five years ago, my wife and I got married. And not a single person at the wedding, bride and groom included, would have bet that we’d still be married by now.

Then again, our marriage was more of a bet than a certainty. We loved each other so much that we both decided, “I will carry this regret to my deathbed if I don’t give this a shot.” So we did the magnificently risky thing, we tied the knot, and…

Twenty-five years later, here we are. Best friends still.

So lemme give you twenty-five hard-earned lessons learned over twenty-five years.