Several years after learning the game, I've discovered various things about PU not generally covered in any detail in PUA literature. I thought I'd chuck some of this stuff out there because, as valuable as PUA approach can be, I still think the science has massive potential for development and I'd like to hear what others have come up with.
My thinking is that the best PUA in the world gets about 30% of the success with woman we potentially could when the science has advanced.
Some of these things I've discovered through reading psychology or other non-PUA literature but all have been validated by personal experience:
SELECTING THE TARGET:
1) Girls who just died their hair red want to get f***ed. A girl who dies her hair red is dissatisfied with her life and wants it to change. You are the guy to change her.
2) Girls who have vices are easier than girls who are not. This is kind of obvious when you think about. A girl who likes a smoke and a drink and the occassional burger probably values her pleasure. Be her pleasure.
3) Any experience that is similar to feelings of romantic love or sexual attraction can easily be mistaken for romantic love or sexual attraction. So,
4) Any kind of shared physical activity is a major bond between you.
5) Creating artificial circumstances which would normally be associated with romantic love or sexual attraction work well as seduction tools. For example, getting a girl to stare into your eyes for longer than normal and hold your hand as, say, part of an ESP test makes her more attracted to you.
6) Taking advantage of a monopoly works as well with seduction as it does in business. On a long train journey or airplane for example, you have the monopoly on a girl sat next to you. If she wants to f*** someone it is gonna be you, there's no one else there. Which leads to:
7) There are perfect "tidal" locations for PUA. Places where a) you have a partially secluded enviroment without too many distractions b) the enviroment is both empty and crowded depending on what time it is. In such places girls literally approach you (say the basement in a coffee shop at lunchtime) as often there is nowhere else to sit or whatever. Unfortunately such locations are rare and tend to disappear with even the slightest change to initial conditions. For example, my local Starbucks has its "tidal" point vanish when they moved the chairs so that no one faced each other.

The more secluded an enviroment the greater the chance of a successful approach. There was a study eons ago in the US where a group of people were introduced to each other in a room that was in total darkness. Amazingly a huge % of the people in the room paired off with each other.
9) Visualization is extraordinary powerful and can be used to create feelings of possessiveness towards you. This works because people are far more motivated by fear of loss than anticipation of gain. With ditsy fun girls for example, you can literally give her heart and watch what she does with it. As silly as this, you can tell this has a powerful effect on her subconscious.
10) For hired guns, the best possible approach is "Surprise me". This deserves a post in itself, but "surprise me" works on about five different levels:
i) You are getting the girl to qualify herself.
ii) You are shaking her out of her hired gun-programme.
iii) You are instantly fun, lively and interesting.
iv) You can screen out dull women quite effectively this way.
v) The HG will sometimes involve the whole bar/ shop whatever creating massive instant social proof. Ideally, you can play two girls off against each other and have them compete for you.
Two words. Best approach ever.
11) The traveller is one of the sexiest men alive. Always look like you are travelling somewhere even if you arne't. You instantly look dynamic, exciting, adventurous and it emphasizes any differences in the gene pool with the girl which will subconsciously make you more attractive (as with peacocking). The worst place to come from for PU purposes is where you are now. You can be liberal with the truth-if you moved from the Czech republic when you were two tell her you're ethnically Czech or something, more detail can come later.
12) Never brag. Scratch that. Brag and never get caught. The trick is to do what magicians do and practice misdirection. Only an idiot would say "I've had hundreds of women". But, in the context of a longer discussion with an emotional context stating "So many women have wanted to be with me for reasons which were shallow and superficial, you know, attracted to me physically or because I'm a popular guy or whatever...but I want to be with someone who gets the real me...do you know what I mean?" can work wonders. With dumber girls, even something as crude like this can work: "Do you think a girl can have too many orgasms.." then change the subject mysteriously after her response.
The key is never to allude to any of your qualities directly but let her fill in the blanks.
13) Following on from 12, the most powerful embedded command is one with NOT in the sentence as in "Don't THINK OF A BLACK CAT". "Don't THINK OF ME IN A SEXUAL WAY" is a lock on some girls who will do just that.
14) Make sure she knows you like giving head. If you don't like giving head, you need to change that. Make sure everyone knows you like giving head.
15) The best approach with almost all women is to recreate the relationship with her primary male model (her Father).
MORE CONTROVERSIAL OBSERVATIONS
This is stuff which I believe to be true but I have more of an open-mind on, and doubtless others won't like. I'll enjoy the flames.
1) Don't use canned openers ever. Canned openers suck.
2) Situational openers work. Pretty much everyone has at some time approach a women with a valid non-PU question and can do it without much problem. Asking a girl the time does not set off your AA and does not set off her bitch shield. However, if she is giving you strong AI it is much easier to continue the sarge at that point. I tend to think new PUA's get thrown in at the deep end-much better to acclimatize yourself to PUA through bypassing AA. To become a master you are going have to do more direct, cold approaches, but for a lot of people that can either come later or just isn't neccessary.
3) Smiling is easier than a verbal opener. A returned smile is basically the approach dealt with.
4) Approaching as many women as possible is way more important that anything else in PUA. Get past that. Even use AFC methods if that gets you past it. It is simple math, you can't get laid if you don't approach.
5) A bad PUA has way more fun and quality of life than any AFC. I feel alive when I sarge even if it is not coming off. A good PUA has one of the most desirable existences in human history. AFC's of the world, you have nothing to lose but your misery and your Warcraft subscription.
6) Women who aren't giving you clusters of AI's aren't worth bothering with. This may not be true if you are very focused on 9's and 10's but:
7) There is no grading system. The whole point of PUA is to make you seem like the prize. The weird thing is, you actually become a real prize by doing this. It is the same with girls. Keep your dumb blondes with plastic tits. I genuinely prefer petit girls with freckles.

Ignore all that stuff about not buying drinks and the like unless you have financial issues. Generosity does not make you a wuss or a beta male, the direct opposite. The big guy buying a round, flirting with the barmaid and chatting up the locals is not a beta male, he's the centre of attention. Just make sure she knows you aren't buying sexual favours. The easiest way to do that is do the same for guys or non-target women.
9) Convention PUA theory is targetted towards extrovert girls and all things being equal they are the ones you target. PUA is pretty much useless with very shy girls.
10) With lone foreign girls who are new to the country and vulnerable (often the most desirable of women) is a rare case where AFC tactics aren't so wide of the mark. You need the confidence to approach of course, but her priority is security in a dangerous enviroment. Forget the cocky part of cocky/funny. Look masculine in your dealings with others but you should be a pussycat to her and have extremely friendly/open body language.
OK, have fun tearing all that shit apart.