Accumulate twigs and branches until you have several dozen, enough to at least start the fence. You can continue to work on a twig fence over time as you get more materials.
Cut the twigs to 3 feet long. Twigs this size will make a small, 2 1/2-foot fence. For a smaller or taller fence, cut shorter or longer twigs respectively.
Pound a garden stake into the ground every 2 feet along the intended fence line.
Cross two twigs at a 90-degree angle and lean them against a garden stake. Press the bottom end of the twigs into the dirt several inches to hold the twigs upright. Weave a figure eight around the intersection of the two twigs with a piece of twine tying the twigs together. Tie a knot in the twine.
Cross two more twigs at a 90-degree angle, again pressing them into the dirt. Offset the second pair of twigs 4 inches from the first pair of twigs and tie the second pair of twigs together. Position the second pair of twigs in line with the first pair. The second pair of twigs must also be placed so that one leg of the second set will intersect a leg of the first set. Tie the first set of twigs to the second set of twigs where they intersect.
Tie a third pair of twigs together, push them into the ground, and offset four inches from the second pair. One leg of the third pair of twigs will overlap a leg of the first pair of twigs and a leg of the second pair of twigs. Tie the twigs together wherever they overlap.
Continue binding pairs of twigs together and tying the twigs to the ones previously set in the ground. When you reach a garden stake, tie the twig fence to it.