We use lots of different cables in the theatre. We have speaker cables, microphone cables, and electrical cables. We use DMX cables, ethernet, DVI, extension cords, VGA, HDMI, and displayport cables.
Every single one of these has one thing in common: The rubber coatings and the metal wires inside all have a degree of shape-memory. They remember the shape they have been forced into.
When you wind any of these cables around your elbow, you are forcing the cable to repeat the same kind of loop over and over. They end up wanting to return to that shape even when you want them to be flat and well-behaved. Even worse, they become confused when you try to coil them up again later, and the conflicting shape memories cause them to become tangled and knotted.
Many of these cables have multiple wires inside of them in different ways. Coiling a cable with the loops going the same direction over and over puts a greater strain on some wires than others inside of it. This shortens the life-span of those cables, and makes them really hard to use.
The proper way to wind any of these is to alternate the direction of the loop with each coil. Professional stage technicians do this almost as casually as they breathe. You coil the cable on your palm in one direction, and then reverse direction for the next coil.
Below is one of the better videos I have seen on this technique. It is from the London School of Sound.