My power lines are made of gray embroidery thread with a touch of CA at each insulator. I usually go 3 poles at a time to get the tension I want, glue it and then cut off the ends.
I start from the bottom closest the pole and work out and up. And yes, I have bumped them plenty of times and gotten horns and couplers caught in them too!! If one comes loose, I just cut out the bad section and replace it. I also start out with the lines fairly tight, they start to stretch and droop nicely, like the real thing, after a week or so.