i used steel cable encased in plastic. its a little more $$ up front but 6 years latter its still on the poles and no rust problems. the first 2 year's i went threw several nylon and rope options. seems like i got the steel in plastic cable from a big box store like home depot, but cant remember. i'm in NY so my line is exposed to all weather as i leave it up all year around.most rope options didnt make it threw a summer, the steel cable in plastic was a great investment in time and $ in the long run.

i used cable ties and twist tensioner like you would use on a sagging gate.