Impro acting, maybe, or have someone point things out like "don't you see how impatient he looks?", etc. - the kind of things parents may do with their kids. Or read a book on etiquette, or hire some kind of body language coach, I'm sure it exists. Or of course a pick-up artist book.
By the way, "There's no rule, you have to learn it case-by-case" is something I often had to say when teaching French to Chinese students; or rather often it was "there may be a rule underneath all those cases, but I have no idea what it is!". Often finding the rule for your native language requires significant effort; and some rules you come up may not accurately describe the way the language actually works.
Body language coaching doesn't just exist, it's an industry. It is typically associated with public speaking, salesmanship, etc, and there are a lot of places (and books, and online resources, etc) to get training. In fact, one of the linked blogs in the OP, "Paging Dr. NerdLove", is completely dedicated to helping men who are bad at inter-personal communication with women (i.e. socially awkward) get better at it, which includes quite a lot of body language training.
It's reasonably well known that body language comprises a significant portion o...
One of the lessons highlighted in the thread "Less Wrong NYC: Case Study of a Successful Rationalist Chapter" is Gender ratio matters.
There have recently been a number of articles addressing one social skills issue that might be affecting this, from the perspective of a geeky/sciencefiction community with similar attributes to LessWrong, and I want to link to these, not just so the people potentially causing problems get to read them, but also so everyone else knows the resource is there and has a name for the problem, which may facilitate wider discussion and make it easier for others to know when to point towards the resources those who would benefit by them.
However before I do, in the light of RedRobot's comment in the "Of Gender and Rationality" thread, I'd like to echo a sentiment from one of the articles, that people exhibiting this behaviour may be of any gender and may victimise upon any gender. And so, while it may be correlated with a particular gender, it is the behaviour that should be focused upon, and turning this thread into bashing of one gender (or defensiveness against perceived bashing) would be unhelpful.
Ok, disclaimers out of the way, here are the links:
Some of those raise deeper issues about rape culture and audience as enabler, but the TLDR summary is:
EDITED TO ADD:
Despite the way some of the links are framed as being addressed to creepers, this post is aimed at least as much at the community as a whole, intended to trigger a discussion on how the community should best go about handling such a problem once identified, with the TLDR being "set of restraints to place on someone who is burning the commons", rather that a complete description that guarantees that anyone who doesn't meet it isn't creepy. (Thank you to jsteinhardt for clearly verbalising the misinterpretation - for discussion see his reply to this post)