Use a cable coil or rope roller. Depending on the size of your cable coil or rope, these devices can be quite handy for untwising or uncoiling. You simply pull one end of the coil, and your cable or rope comes rattling off as quickly as you can pull it.
Untwist or uncoil your rope or cable in the opposite way you twisted or coiled it. Put your forearm into the center of the coil. Grip the top of the coil between your thumb and index finger.
Untie the knot you created at the end of the coil when you put the cable or rope away the last time you used it. Do this with your opposing hand.
Pull as much rope or cable as you need to do the job hat you're about to do. Using your forearm as a rope or cable roll, undo the coil one loop at a time until you have as much rope or cable as you need. If you measure carefully and don't pull off much more than you are actually planning on using, you can save yourself a lot of energy and perhaps keep from obtaining a tangled mess.
Cut off the cable or rope that you want to use from the roll, if you plan on cutting the coil and using it in that manner. Once you have it cut, you can use the cable or rope freely. Tie the loose end of the coil.
Tie the unused coil with a tie string to keep it secured while you are doing the job, if you don't cut off an end for your use. If the cable requires to be installed with the other end of the cable, locate that end and install it or plug it in.