Place a 3 foot metal stake on one side of your path and drive the stake in so that 1 foot remains above ground. Measure across the path 4 feet and repeat for the other side of the arch. You can space your stakes further apart if you want more room. Simply make your willow branches longer to accommodate the increased width.
Cut two willow branches 16 feet long. Trim off all the small branches, twigs and leaves. Arrange the branches with the narrow ends overlapping by 2 feet.
Cut 1-foot pieces of 16 gauge wire using wire cutters. Wrap the wire around the overlapping areas of the branches starting 2 inches from the overlap. Wrap the wire twice around the branches, keeping the wire as tight as possible. Twist the ends three times and trim off the excess wire. Repeat this for the other overlapping end and every 6-to-8 inches in between.
Stand up the branches, bringing the ends toward each other. Place the ends against the inside of the metal stakes. Raise the branch 1 inch above the soil to prevent the branch from forming roots. Attach the branches tightly to the metal stake using at least two wires per stake.
Space your arches 1 1/2-to-2 feet apart. Cut small willow branches to fit across the width of the three arches together. Weave the branches along each side. Wire the ends of the branches to the arches to help stabilize the arches. Place the wire diagonally, like an "X."