Cut all twine into 36-inch strands. Knot four strands together and secure the knot to your cardboard sheet by pushing a T-pin into it. T-pins have a crossbar to make them easy to push in and pull out of a cardboard sheet or macrame' board.
Hold two strands in each hand. Twist the doubled strands together for one inch and make a second knot. Repeat twisting and knotting until you reach the other end of the strands.
Coiled the knotted 4-strand twine around the original knot one full turn. Stitch in place by pulling the needle through the original knot from underneath and back down through the inner side of the coil. Make four stitches in an "X," pattern to secure the first coil.
Continue to coil the 4-strand knotted twine around, stitching the coil in place every inch between the previous coil and the inner edge of the next one. When you reach the end of the knotted twine, pull the end knot open just enough to push the first knot of the next length of twine through the hole to connect them. This should hold the two together long enough for you to stitch the next coil into place.
Continue coiling the knotted twine until you have used every strand. If you want a larger rug, cut another skein of twine into strands, knot them and add them to your coil.