This probably isn't what you had in mind, but reading a few erotic novels for women made the biggest impact on my sexual interactions.
For most men, sex is pretty simple. Slide it in and out and suck on a titty or two and you're good. But for women, good sex is an experience and erotic novels revolve around that experience. You can see how the sexual dance starts from the very moment the man and woman meet. There is also an emphasis on dominant and dirty sex. Women eat that shit up! And you'll probably come to love it too, especially once you see the effect it has on them.
Since I have started becoming more sexual and having fun with building a sexual experience with my women, sex is more fun, satisfying and memorable. A girl loves spontaneous sex in a public place or dominant dirty sex pinned against a wall... as well the build up leading to it.
You might also be interested in Karezza. It's a new way of looking at sex, one that isn't climax driven. Its a good way to conserve your sexual creative energy if you're into that. Just keep in mind Karezza is pretty gentle and better saved for experimenting with an already established sexual partner.
I tried looking into technique based sex guides, but it was all too clinical for me. I've learned the best stuff from erotic novels and just plain old practice and experimentation. But the GC sex stuff and especially Hector's kinky series are worth looking into if you haven't already.
