I generally use 8mm Hempex (synthetic hemp, polypropylene) for the ridge, and similar in 3-4mm or paracord for guys.
I usually hook the tie-outs to the ridge with these rather than threading it through as I find it easier to set and strike that way. My guys usually have mini biners at one end for the same reason. YMMV.
Anything you can use to tie it to something and which doesn't break easily? I mean, it's not exactly rocket science