I use the first wrap over, and all others under method, so the string end is sandwiched between the first wrap on top, and all the others below. I first pull the string tight before winding, not leaving much slack at all, but not too tight. In this way, I usually end up with 3-4 wraps max around the post, none overlapping. My wraps never go all the way to the bottom of the post, which would be 5-6; that seems excessive to me. I've found no problem loosening and rewrapping strings if I messed it up, and have also reused lots of string sets with no problems, but you need to leave enough extra string to reuse them on another uke.