How to toughen up your iphone 5 cable?

So I'm wanting to toughen up my iphone cable I just can't figure anything out on the top of my head what to use. It always rips up towards the ends of the charger from it bending so much I was thinking of heat shrink but not sure if that would make it any stronger. Can anyone think of anything at home that might do the trick? Or something cheap I can buy to make it better?

You can easily take the spring out of a common click pen and place it around the cable where it is prone to bending. This should stop it from happening.

Usually i wrap the end with a little duct tape; its really strong and prevents it from wearing out.