This technique is one I developed over the years as I refused to let the presence of other people in the house dissuade me from getting pleasure.
Stroking, which almost always takes lube of some kind (unless you are just tugging) can be loud and messy. If there is a chance that someone could walk into the room at any moment, this makes normal masturbation impossible.
Women actually have it lucky in this regard. They can thrust something into themselves (the equivalent of male stroking) or they can just rub their labia, usually concentrating on the clit. This second method is much cleaner and easier to conceal.
However, males can do this as well, it's just not as obvious. First, you will need to be hard. It doesn't work well otherwise. This shouldn't be too much of a problem. Just look up some quick porn online. Then you will probably have to unbutton your pants. I wear skinny jeans, so I have to. Others may not. You decide. You need to be able to comfortably place you hand on your dick. Reaching into a tight pair of pants is very uncomfortable and annoying.
You will also need a couple squares of toilet paper, or a tissue. This method is cleaner than stroking, but not entirely clean.
With your hard cock laying flat on your stomach, use the thumb and index finger of one hand to pinch the part of the shaft on the side of your cock that is facing away from your stomach, just below the head. When I say pinch, I don't mean clamp down. How much pressure to use is up to you, but you are not trying to bug someone. You are pleasuring yourself. Now, instead of just holding it, swiftly tighten and release your pinch grip, continuing this for a good length of time. Don't pinch the whole shaft; that will just be uncomfortable. Only pinch the big tube that runs up the middle. You are targeting the corpus spongiosum.
You may want to try both hands and see which one works best. I'm a righty, and I use my right hand for all methods of masturbation, except this one. For some reason, it just feels so much more correct to use my left hand. Plus, it leaves my right hand open for working my computer.
You will need to place the tissue between the head of your cock and your stomach, because after about 2 to 5 minutes of prolonged stimulation, you will start to leak precum profusely.
I absolutely adore this method. It's quiet for one thing, because there is no squishy lube needed. Secondly, it is easy to clean up, assuming you have not cum yet. That makes it perfect for extreme edgers like myself. Unlike stroking, it is really easy to stop and pack up at a moment's notice. And third, it is extremely stimulating.
Pinching is to males what rubbing the clit is to females. It is straight forward, raw, unfiltered stimulation of the most sensitive part of the genitalia.
I usually use this method during the day while there are other people around. It's also an excellent way to get rid of morning wood if you just need relief. However, the resulting orgasm can be a little lack luster if you are not really concentrating, so consider pinching as a method of foreplay before you get to full-on stroking.
I'm circumcised, so this is really easy for me. I don't know if the foreskin will get in the way or not. I would imagine not, but I don't know. Friction is really the key here, so the foreskin sliding around may make it hard to get the fullest effect.
Hope you all try this and like it.