I'm incredibly hard on my notebook chargers. I drop them, accidentally yank them from the wall outlet, drive over the cable with my office chair, and drag them about. So anything I can do to make them last longer (which doesn't mean taking extra care of them) helps me save money.
On the whole notebook chargers put up well with mishandling, but I've found that there's one vulnerable spot on pretty much every charger I've owned - the point where the low power cord exits the charger brick. Here the cable is vulnerable to fraying and wear, and once that happens, you're facing a bill.
Enter Python Cords.
Python Cord is a simple silicone sleeve that fits around the brick, and wraps around the cable to offer additional strength for this weak point.
And it works. I've tried several homebrew solutions to this cord fraying issue - using tape and even Sugru - and nothing works as well as Python Cords do.