Cable crackling can be caused by either the cable or the connectors. Try localizing the problem by gently wiggling and squeezing the cable and connectors. Connectors can get dirty and cause crackling. You can clean the phone plugs with a pencil eraser (make sure you get all the crumbs off). Loose contacts in the phone jacks of the amp or guitar can also cause crackling as you "make" and "break" connections. Try borrowing a cable from a friend to see if the problem is in the cable, amp or guitar. If the cable is the problem and the connectors are ok, you may be able to repair the cable by cutting off the bad section and installing a new connector. I always spend a little extra money to buy a cable with a lifetime guarantee. I have only had one failure in the last five years and the dealer replaced the cable without question.
As James said, excessive bending of the cable can flatten the center conductor and damage the shield. All cables have a minimum bend radius - be careful and don't coil your cables too tightly. Be careful to keep crimps out of your cable by keeping amps and other equipment off of cables.