Honestly, there is no certain way for someone to make a ghillie. As long as its got some burlap on it and has way to hold some natural vegetation.
The ghillie I still use today was just something I made in one night for a game. I wasn't expecting it to last, but here I am 3 years later and still using the same one.
All I did was use hot glue to glue 2-3inch strips of elastic band all over the back of a pair BDU pants and jacket, then buy 2 sheets of burlap that already had a realtree like print that was printed on one side, slice it into strips about 2 inches wide and anywhere from 6 to 15 inches long, tie a knot in the strip in random places from the top, middle, or bottom, then glue the knot onto the BDU's working from the bottom up.