This will be a very short instructable, since it is SO easy. I was a boyscout when I was young and, yes, I did learn some useful things back then. So when we set up our new awning lately, I recalled the simple line-tensioners we made back in the days when we went camping with the boyscout group. They’re easy to make, simple to set up and cost next to nothing.
Step 1: Gather Wood and Drill Some Holes
You'll need some (scrap-) pieces of wood, around 50 x 20 x 5 mm. Drill three holes as shown in the image of about the diameter of your rope (make them slightly larger). Don't sand the edges, since sharp edges make them keep tension better. There's no need to make them pretty.
Then, take your rope and thread it as show above.
Step 2: Set Them Up
Now set up your awning / tent / pole / etc. with your new tensioners. You can adjust them by tilting them and pulling your rope accordingly.
You can find the original post here.