You might find the show "Lie to Me" really interesting; while the show itself is fictional, the science of facial expressions is true. I believe it was Haggard and Isaacs who are credited with first exploring this topic; it's been a while since I read about the studies done on it, but from what I can remember, they took every possible combination of facial muscles and, through stimulating muscle combinations and taking these studies to isolated communities, identified some 1,000 or so (if I remember correctly) muscle combinations that have meaning, as well as what that meaning would be. There are only a handful of professionals who are actually qualified to use these studies in research (by which I mean, reading the face for a qualitative study etc), but it's a science that most people have some comprehension of naturally. These muscle combinations are consistent across cultures and communities regardless of location and exposure. There's a more thorough summary in Malcolm Gladwell's "Blink," (and I think Paul Ekman has several books on the subject that may be fairly accessible) but I really enjoyed obsessing over "Lie To Me" for a while in high school. I think I'm relatively low on the spectrum, so I can't say with certainty that your experience will be the same as mine, but after cramming episodes of "Lie to Me" I had a much stronger understanding of facial expressions, and with practice I think that, depending on the situation, I may read almost as well as a neurotypical person (and in certain situations, perhaps even better, simply because in the situations I'm referring to, I've had more exposure than most NT's and my understanding is much more rational, rather than relying on instinct). Now, when I see someone smile, I look to see if the corners of their eyes are crinkling with the smile to determine whether the smile is real, and similar cues for other emotions. I guess what I'm saying is, just because it doesn't come naturally to us doesn't mean it's beyond us; where there's a science, there's rationality, and where there's rationality, there is the potential to learn; by studying potential expressions, you may be able to at least improve your abilities, even if it will never be as natural or accurate as you'd like.