Place stakes into the corners of your field boundaries. Tie string between them to mark the fence rows. When you set your posts, use the string as a guide.
Dig post holes for your posts at 8-foot intervals along the fence line. Each post hole should be set into the ground 3-feet deep. Insert the end of a 6-inch diameter timber post into the post holes along the row. In the corner post hole and the 2 holes on either side of it, insert an 8-inch diameter post. Fill in the soil in each hole so that the post is held upright perpendicular to the ground.
Nail a board vertically between the corner post and the first post in the fence line in either direction to act as a fencing brace. The post should be set 6 feet off the ground. Nail a second set of boards between the first and second 8-inch-wide post in the fence rows. Repeat this process for each corner.
Wind a strand of wire 4 times between the bottom of the corner post and the top of the first post in the fence row. Wind another set of wire between the second braced post and the bottom of the first post. Secure the wires by nailing them to the posts with fencing staples. Insert a metal pipe in between each set of twisted wire and tighten the wire by twisting the pipe until the wire is taut. Slide the wire behind the brace board to secure it. Repeat this process for both sides of the corner posts.
Tack wire strands from one end of the fence to the other using fencing staples. Clip the wire with wire nippers. Tighten the wire by attaching both ends of a fence stretcher to the end of the wire. Ratchet the ends of the fence stretcher to take up slack in the wire. Nail the fencing staples tightly in place. The fence may have as few or as many strands as you wish. There should be at least 3 strands -- one that is 2 feet off the ground, one that is 4 feet from the ground and one at 6 feet off the ground.