I'm not sure how the woven wraps work - is it the sort of thing I can make myself, if I can get my hands on the right size fabric? Or do I need some kind of specialty fabric? I just don't think I can afford a woven wrap right now -- even the used ones are pricey -- but how hard are they to make, really? Any experience with this or advice? I've used a Moby but I'm ready to upgrade for this next babe. TIA!