This is really just breathing, and stroking, and clenching your PC muscle. THAT'S IT. We would like to have it more complicated, to have more techniques - and yes, these techniques do exist and are useful. But basically, it's breathing, stroking, clenching muscles. And so much enjoyment can come from it.
Okay, it's breathing, stroking, clenching AND FOCUS ON INTERNAL FEELINGS. Given that I have a few years of regular zen meditation under the belt, this will probably help with the last part enormously.
But really, THAT'S IT!
I'm not claiming that all the good stuff that happened recently, like getting to know way more people (yes that includes young pretty females of the species), becoming more bold and assertive on the job, getting more done on my private projects, doing more sports, adhering more to my diet, etc. .... I'm not claiming that all this is due to tantra. I think this is a system of mutual reinforcement, a feedback loop... what the tantra adds is the good feeling of being able to produce good feelings at will. (Notice what I did there? *g*). From that comes more boldness, which helps with the sport and diet routine, which in turn produce more good feelings and make it seem easier to do more tantra, and so on.
It's one part, not the whole thing, to be sure. But it's a highly useful part!