Measure and mark the area for the posts. Depending on the fence, the poles are ideally set 6 to 8 feet apart. Mark the measured spots with wooden stakes.
Dig the post holes. With a post hole digger, dig the holes 1/3 the total length of the fence post. The hole should be twice the diameter of the actual post.
Shovel 2 or 3 shovels full of crushed river rocks into the hole and set the pole. Push the pole down into the rocks and straighten it.
Fill the hole around the pole to about 1 foot below the surface with the crushed rock.
Fill in the remaining foot of space with whole river rocks. Work with the rocks to fit them as tightly as possible into the remaining space.