Its fairly simple. Let me see how well I can describe it to you. Start by soaking the paracord in water for a couple hours this way it will stretch and when dry become even more tight.
Make a loop that runs from one end of the item to be wrapped to the other with the end of the loop( the loop, not the open end)hanging barely off the end. For example if you were wrapping a AR stock, start with the end a the butstock then run it the length of the stock and back. Then from the butstock end start wrapping over and over and over again. Once you get next to the charging handle all you will see of that legnth wise loop will be a little loop end sticking out from under all your wrapping. After making your last wrap, tuck the end through that original loop hole and pull the loose end next to the butstock. This will pull the loop closed next to the charging handle and tie it off. Then just cut the loose end next to the butstock and burn the tip so it won't unravel.
Done
Now wasn't that clear as mud???