I am not familiar with that technique and to be honest, I don't recall any training or practice to help holding the camera steady. This is because of two factors: holding the camera correctly, and understanding the impact of shutter speed on motion.
I suggest doing a google search on 'how to hold a camera', where you will be linked to many stories such as this one. Providing the proper support to your camera will bring significant stability, and reduce 'shake'.
Of course, ensuring that you are shooting at the proper shutter speed is critical as well, and likely the largest noticeable impact to your images. An old 'rule of thumb' for full frame cameras was to ensure that you shoot at a shutter speed above the 1/focal length of the lens you are using: if you are shooting at 70mm, ensure your shutterspeed is above 1/70th. Likewise, if shooting at 200mm, shoot above 1/200th. In general, you should ensure that any hand held shooting occurs at 1/60th or above, though these days with stabilization and crop sensors, it is no longer a very useful gauge, only a simple reminder to ensure you are shooting at the proper shutter speed for your conditions.
You will notice photographers using long lenses with monopods or tripods, such as during sporting events or perhaps shooting wildlife. This is because many use very long lenses, and they often need shutter speeds lower than the focal length.