Properly coiling your audio cables is the most important thing you can do to care for them. Most of you probably already know how to do the "half-twist" when coiling the cable. However, recently my friend Jeff showed me an even better way to coil cables.
To coil with the standard half-twist method, you gently twist the cable while making each coil. This removes some of the twisting tension in the cable. That tension would normally make the cable want to twist up and tangle. However, since you removed the tension, it is as if you had coiled the cable on a spool. This is excellent practice and provides years of reliable use.
But, if you have done this for many years, you have noticed some problems with this. First, to keep the cable from coiling like a phone cord, you have to diligently unwind the cable -- putting back your half twist with every coil. Further, these coils do sometimes get tangled without much effort. The cable also takes on a permanent coil and does not lay perfectly flat or straight.
This is where the over-and-under method comes in. This method will literally allow you to throw a 100-ft cable and it will not get tangled:
What's cool is that it works for more than just cables: garden hoses, ropes, and... erm... that's all I can think of.
You can read more about it on Wikipedia.
 Video from Chris Babbie Location Sound