These fences are stronger than a Stone Hedge.
To make a fence, build a start/corner post, then right-click on the post to build in a cardinal direction; to change direction add a corner post at the corner. To build a gate, leave a 2 tile gap between two start/corner posts and right-click on a post to enable the gate option.
It is very important to have the the starter post be properly aligned in it's tile, especially if you will be introducing more than one gate in the fence, and therefore placing more than one starter post.
Costs per tile