Drill pilot holes in both ends of a 4-by 4-inch 48-inch long section of hardwood about 12 inches from the ends. On the opposite side, drill two more pilot holes 6 inches from the end. Screw eye hooks rated for 200 pounds or more into each of the holes.
Secure both ends of the single-person sling hammock into the hooks 6 inches from the ends of the piece of hardwood using S-hooks.
Screw two eye hooks into the underside of a strong tree limb at least 10 feet from the ground. These will anchor your ropes without hurting the tree.
Hang sections of chain with S-hooks or hammock clips from the hooks on the tree branch. They should be long enough to hold the hardwood bar about 6 feet from the ground.
Hook the other ends of the chains to the hooks 12 inches from the ends of the hardwood bar, adjusting them until the swing seat hangs straight.
Sit in the swing and check to make sure it is hanging at the proper height, adjusting the chain if necessary.