Where to put a cable tie on an electrical cord?
How do you unfurl electrical cables?

Unwinding a lot of extension cords; I usually start at the socket, plug in the "plug end" of the cable, and unfurl from there.   Otherwise I have no idea where to start.  

Generally unfurling a cable flows best when you do it in reverse: start unfurling from the end you finished furling.   Otherwise it tends to tangle. 

So that says start furling at the socket end, and that's where the cable wrap should go.  Also if you don't need the full length, you can use the wrap to re-bind the part of the cable you haven't unfurled.