Sorry if part/some/most/all of this post comes off as creepy, and I'm hardly qualified with women, but I can offer you a few body language and mentalism tricks.
1: When you want her to agree with you, if at all possible, get the request into HER RIGHT ear. It doubles the chance of her agreeing if you're asking her to do something.
1.1: On the other end of the scale, some manipulation can be done by getting her to disagree with you. Things you would prefer to be denied, ask her in HER LEFT ear.
1.2: Similarly to (1), look her in HER RIGHT eye when you want her to agree. LEFT eye for disagreement.
2: Another agreeing trick is to touch her lightly on the arm when asking for something you want her to agree to. This is a 'dominance is sexy' thing that society has, and works even if the subject identifies as dominant and the user of this technique as submissive.
2.1: However, if this fails, it fails horribly. And if YOU fail, you fail horribly. If you misjudge this (touch her too hard or if she ends up disagreeing anyway), she will remember you as 'the creep who tried to touch her'. I recommend only doing this once most of the other techniques listed here pass. This contact must pass as PLATONIC
3: When you want her to agree with you, nod your head. This exerts confidence and dominance (Yes, it's ANOTHER one of those subliminal 'dominance is sexy' things society has) and she will be inclined to agree with you.
3.1: See 1.1, but for the technique mentioned in 2.
4: If you can, try and teach her how to play a game. A person who is willing to let you teach them how to play a game places great trust in you and this is not missed by your subconscious. This works with any unfamiliar game, be it trading cards or D&D, so long as they don't know it beforehand.
5: BODY LANGUAGE! For a male, head up slightly, but not so much as to be looking down your nose at the other; chin out and up slightly. This gives you a more prominent jaw which indicates testosterone and makes you seem more dominant (there are a lot of these dominance is sexy things here, aren't there?). For girls, head down and chin tucked in gives your face an angled and more beautiful appearance (unlike males, this has nothing to do with hormones, just aesthetics).
5.1: Pay attention (but don't stare) at her feet. People tend to stand and sit with their feet pointed (somewhat) to the object currently occupying their attention. If the feet are angled out, she is not paying attention - a poor time to utilise many of these tricks
5.2: Pay attention to what you and her are holding! People are more serious when they are holding something heavy, and less serious when holding something light. Adjust your banter accordingly.
5.2.1: Speaking of banter, NAMES. Repeat her name frequently, but don't overdo it. "So, Sophia, what do you like to ..." as opposed to 'So, what do you like to do..." It makes them like you more and is one of the more foolproof methods here
6: If going for any physical contact, make sure the body part is warm. If (for example) your hand is cold and you shake hands, her subconscious goes 'oh, hey, cold hands. I don't like that.' The opposite is true for warm hands.
7: If you suspect she isn't saying everything about a situation or is edging around it, yet you must know the answer: Look at her best friend, who will usually give the subject's actual feelings about a topic away with her body language.
7.e: This needs an example to be clear. If you ask her whether she likes coffee (a good lead up into MANIPULATION tactic 1), and she seems to skirt the question, look at her best friend (if present). Her best friend will subconsciously give her away with a nod or shake of the head when the question is asked - it is easy to miss, and looking away from your target while asking isn't a great idea.
OUTRIGHT MANIPULATION:
1: Get her a drink of coffee. Just like the right-ear/eye trick above, this increases your chances of her agreeing with you - but if she disagrees, it will be more of a disagreement than if she hadn't had a coffee.
2: Horror movies: My personal favourite manipulative tactic. There is a reason couples often start relationships at the movies, doubly so if said movie is a horror movie. At first, this seems counter-intuitive; however, think about this: When you get a fright, or other effect of a horror movie such as adrenaline reactions, your heart starts beating FAST. This makes your brain spin into overdrive and your brain rationalises this fear into an attraction to your partner/date. Your partner will have the same reaction. This method usually never fails unless the movie was incredibly poor (and even then you can laugh it off and increase the relationship). The hardest part is convincing her to see a horror movie
3: People in shock are more susceptible to manipulation tactics. This is my least favourite manipulation tactic; it feels cheap to take advantage of shock.
3.1: In the same vein, people are less resistant to manipulation when waking up or about to fall asleep.
4: If you want her to elaborate on a point, simply remain silent and before long she will elaborate or change the topic.
DEDUCTION:
1: If you're in a group and she sneezes or yawns, she will sneeze or yawn away from the person she considers most important (Ideally, you)
2: If, while holding a conversation with her, she is biting her bottom lip, it is a sign she is attracted to you. Same applies if you're biting yours.
3: If you think she's lying to you about something, check if she's reacting to an adrenaline rush. When someone lies, the lie is accompanied by an adrenaline rush. The most common sign is an itchy nose, but this is not the be-all and eld-all.
4: Look at her handwriting. Large and neat handwriting is a sign of someone who wants attention, large and messy is just a sign that they have difficulty writing. Small writing indicates a shy character, although if it's messy it could just be a sign of trying to cram as much as possible onto the page, which indicates their mood at the time it was written.
More to come if requested.