Trouble with Super-O

what are some contractions techniques which have been successful?

What did the trick for me was a regular kegel workout, which enabled me to control my pelvic muscles separately. Playing around with the different muscles (clenching them one by one, back and forth) sparked my first serious pleasure waves. I wrote a detailed (and long) entry about that in the "My first super-O"-Thread.

Alternatively, you might try the "do nothing"-approach. It prevents you from trying to force things to happen and thus "clenching the spark away".

Cheers, Unfug

...I got some intense involuntariness, that tightness does not translate into an orgasm (also, the involuntariness did not lead to anything).

That's great that you have been doing some reading. By now you should know that each individual needs to find his own unique path to the Super-O and the path is far more a mental exercise than a physical one. This journey requires you to make a paradigm shift in thinking even to the core question of What's an Orgasm?.

What can I do to take the next step into a Super-O and what are some contractions techniques which have been successful?

I get the feeling that you are chasing after a physical technique you expect to land you in the Super-O zone, this is a trap. Please read 'Neros' thread The Myth of Super Orgasm. @Unfug 's suggestion to just practice Kegel exercises instead of concentrating on specific contraction techniques is sound advice. As your pelvic floor muscles develop tone and endurance, follow your own intuitive adventurous experimentation. Let the resultant pleasure be your guide. While diverse contraction regimes have been reported in this forum some men still find such regimes ineffective, hence, you may want to try the 'do nothing' technique as also suggested by @Unfug (please see the thread -> "Do Nothing" What does that mean?
Good Vibes to You !

[USER="56824"]Psup88[/USER] I'm with @Unfug in that I'll vote for the "do-nothing" technique for starting a session. You can't go wrong with it. If nothing develops, your expectation was not set too high and you won't be disappointed. If something good develops, you now have a technique you can trust! Good luck!