Well, it depends on the cord.
You are probably wrapping it into a bunch of loops all going the same direction, essentially a big spiral. Each loop in this spiral amounts to one twist in the rope. On a line made by twisting three strands together this works fine, since the line will absorb the twisting and un-twisting effect, but in a braided cord you will generally get the infamous tangled mess.
The way to avoid the tangled mess with the spiral coil in braided line is to carefully un-coil it, taking out each twist as you go. You also shouldn't make your coils to small, since eventually your cordage will develop a memory of whatever shape it has lived in.
A better way to handle braided line is generally to use the butterfly coil, as illustrated here:
http://www.youtube.com/watch?v=R8X90k5U6vQ
This can be done with any size line, and it's usually my habitual coiling method.
Another good way to handle a bunch of cordage is to stack it into a bag of some sort. If you have a chance to look at a kayaker's throw-bag it illustrates this process. This is typically how SAR teams handle rescue ropes.
The other no-tangle method that I use is called the reverse coil, but I haven't been able to find any online videos of how to do it though. It's a bit tricky to do well and you have to be sure to un-coil it properly or you get a bunch of knots. It's really only called for with something stiff and hard to handle though (something like high-pressure hose).