Here's a shot of a bottle top tension in action. In this pic you see the yellow tent, the aluminum pole supporting the peak, the orange of the paraco...
Line tensioners make setting up a tent much easier than tying off rope, and they're incredibly easy to make. Here are a couple I made from the screw-on lids from soda and juice bottles. The only tools you need are a drill with about an 1/8" bit and a sharp utility knife. I also used some channel-lock pliers to hold the lids while drilling.
Drill the holes similar to this. Precise placement is not necessary. You want two holes on opposite side of the lid, another hole near one of those first two holes, and the last hole about 90 degrees off from the first two holes.