Apple's MacBook Pro and MacBook Air charger is great because it includes a built-in way to wind up its MagSafe cord. The problem is that it's kind of easy to bend and fray the cord over time where it goes into the power supply, even with the extra reinforcement Apple added. Thanks to a quick winding technique, however, you don't have to worry about frayed cords and potential electrical hazards.
Your MagSafe charger deserves gentle treatment
Start by leaving a couple inches slack where the cord goes into the power supply, then bend the cord so it's parallel to itself and running down along the wide part of the charger body.
Start by making a gentle loop in the charger cord...
Now loop the cord back up and wind it around the charger's fold-out tabs as you normally would.
...now loop back and wind up as you normally would.
This technique takes the stress off the base of the MagSafe cable, and that means you're less likely to need to buy a replacement charger for your trusty Mac laptop.