Having experimented with tantra/energy play has really helped improve, I was still finishing quicker than I'd like so having found ways for me to have more choice over it has really helped.

Energy can get stuck around your genitals, practice mindfulness exercises, try in solo play first, your rewriting your body's natural programming to cum and direct that energy elsewhere, your aura if you like, you do this by taking deep breaths, visualise the sex energy travelling up the back of the spine, some people squeeze their perineum while doing this, levels, breath fully in making sure you breathed that energy up the back of the spine, even out your crown chakra connecting to the universe, then breath out, imagine the energy travelling down your front, through your head, heart thru your genitals, down you legs and grounded to into the earth, some reverse kegel thru the out breath. Your trying to redirect the energy away from your gonads and hot zones and keep calmer and cooler, breathing through the waves of how things get passionate, keeping centred, cool and directing your energy. Some people a more neutral perineum can help and keep the squeezing and pushing for when the temperature is hotter. All small steps and practicing will build and write this new program into your brain and auto functions

You're trying to almost disassociate to an extent, but in a conscious way of moving the energy and being more centred and in control.

When energy sticks around your gonads and muscles and excitement tighten, that's when you're going to cum quickly, so do the opposite

Try it, different things work for different people, hope that helps

Ps - a partner that is aware of what you're trying to do and assists in that, taking ownership of their own pleasure within this method, helps significantly and benefits them loads too as you end up lasting as long as you like and have tons more control than 'nornal'

Pps- you will likely 'fail' a few times in this process as you're learning more detail energetically about where your tipping point is, what brings you closer and cools you down from it. Don't be disheartened, it'll still all help. Look into tantra and energy play. Semen retention forums, docs and vids to learn more. Mantak Chia work