hey guyyssss, i made the straps like this:
i cut 2 strips of fabric, placed them wrong sides together, and sewed each side then pulled them right-side-out. [like you would making normal straps]
then i bought this spool of rope-like stuff...i think i bought it at jo-anns..its not hard to find.
i just put a safety pin on the end of the piece of rope and pulled it through the strap i made of fabric
its pretty easy, and turns out great!
i'll try to post a tutorial..i made it a while ago, so i'm trying to remember how to make it...but i'm working on it