The key to learning how to delay ejaculation is to train your mind and body to perform as you wish it. There are many things you can do to master the art of ejaculating. The most vital thing is to simply know your body well and control it.
But first you have to know your body. Know what it can do and not do. Understand the signals it gives you and act on them. We all have different points that draw us up to the point of "No Return" Know your point, know what takes to get you there and learn to not reach that point so fast.
When you are thinking you are going to have sex a good thing to do is to masturbate and before you ejaculate stop. Wait a few minutes and do it again. Train your body not to release until you are ready to release. Do not give in to the urge. When you feel the need hard and fast to cum then reach down with your strong hand and grab the base of your penis and squeeze hard.
Learn the breathing routine. When you are close to releasing the ejaculate, take a deep breath through your nose, as deep as you can and hold it for at least five seconds and up to ten. Then slowly let it go through your mouth. Do this repeatedly until you are in control again.
Change positions. There are so many positions that you can try. Do not be shy and just go for it. Slow down your strokes and breathe. Missionary style is NOT the best for controlling your ejaculations.
Something you can try as a technique to train your body before having sex is the cold water treatment. Whenever you take a shower the last thing you do is to shower your genitals with cold water, icy cold is good. The idea behind this is the penis and the testicles need lower heat that is why they are outside of the body. This keeps the production of sperm at their best.
The goal of doing this, and you can alternate off during the say shower cold and hot, cold and hot, just make sure the last is cold. What this does is give your testicles a teasing work out. Where the cells and the muscles contract and expand, contract and expand reiteratedly. A great work out do not you think?