Learn how to use your tongue

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Also, if you get a girl to talk during sex, odds are she'll enjoy it more. Female orgasms, unlike those of men, are mental - yes, they can be achieved without ANY physical stimulation. Your most powerful sex organ isn't your cock or your tongue, it's your vocal chords.
The second piece of information I found invaluable is that women derive extreme sexual pleasure from knowing that they are pleasing the guy. Mention that it turns you on when women moan during sex. When she does it, reward her by verbalizing how much you like it: 'Moan for me more baby... Ooh, your moans turn me on soooo fucking much' or anyting along those lines. The point is to establish a connection between her pleasure and doing whatever it is that turns you on, sometimes called 'anchoring'. If you do it consistently, you can completely change the way she acts in bed - I've turned a sweet romantic girl into a wild animal by teaching her to associate pleasure with scratching my back (yes, I am weird... fuck you)
You can also try more direct hypnotic commands. Ask her how (fucking) good she feels, then tell her that she feels even better when she moans. Prompt her to moan, then ask if the pleasure is more intense. She only has one response to this, and it's the right one. You've established that moans feel great for her, so prompt her to moan more, and remind her how much it turns you on.
It's very fucking repetitive, but trust me, this shit works. If you wanna learn more, I've gained a great deal of knowledge from David Shade's phone sex manual. I keep yapping on about it, but it's the single most valuable resource I've stumbled upon in the community.
Enjoy.