One of the most simple lessons that I got a lot of milage out of is: don't be afraid to state the obvious. A lot of conversations and human interactions are more about the positive vibe that's being created than about the content. (Somewhat less so in these circles.)
This is good advice for continuing an existing interaction with people, which I already feel like I'm pretty good at, but what I'm not so good at is starting such interactions with people I don't already know.
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.