All you need to make your own is a sharp knife. Otherwise, it is hard to do with just your teeth.
and duct tape, you cant forget the duct tape...
no really, it works good for low voltage electrical tape,
EDIT: also, heres a pic of how you need to wire it up, and most cables that you buy stock, will say patch if they are a patch cable, and generally the ones that dont seem to be crossover, or custom made cables,