Well, I'm new to pitching tarps and rigging, so it's pretty much all a "knot" to me. I did get some more line, 65lb test fishing line. It was really inexpensive, and it's still slippery, but not as bad. I think it'll be fine for guy lines and tying off stakes, but I tried using it for a ridgeline, just practicing with my heavy department store tarp, and it kinda worked, but stretched a lot. I'm going to make a tarp with a built-in ridgeline so it won't be an issue. I'll look up the suggested hitches/knots/whatever and try them out.

EDIT: What I mean is a reinforced ridgeline with tie-outs at the edges.