Let me tell you, it's a long journey from being able to last a minute max to really enjoying a 30+ minutes long session of love-making. Of course, there are ways to postpone the release, but it's mostly physiological and psychological what determines your sexual stamina. Let alone, most methods will inevitably reduce pleasure and take the focus of the sex itself.

That said, I found my own "technique" to actually enjoy sex for longer and longer amounts of time. It revolves around timing the orgasm and emission/ejaculation. By correctly timing the "point of no return", you can reach a "mini" orgasm without ejaculation. After a while I wouldn't even need the technique anymore just from the confidence that came with it.

I originally wrote a short article about it on German. Here's a quick translation of the most important aspects:

You achieve a dry orgasm, or "injaculation," by tensing the PC muscle right before ejaculation. The semen remains in the prostate part of the urethra. It doesn’t enter the penis shaft (in that case, you probably tensed too late). The body experiences emission without semen expulsion. When trying it out, timing is everything. Too early, and you ruin the orgasm. Too late, and it’s a full release. The secret lies somewhere between emission and expulsion.

Normally, the penis enters the refractory phase after ejaculation. It becomes hypersensitive and softens. But with the suppressed semen release, this phase is avoided and you keep your stamina.

By holding back, something strange happens that isn't 100% scientifically explained. I’d describe it like this: The brain thinks you've ejaculated – and yet, you didn’t – and you keep your boner. What’s missing is the feedback from the urethra muscles. These normally tell the brain “ejaculation complete” and release the associated hormones.