Fold gold fabric into a square. Tie a piece of string to pencil, like a compass. Trim string to half of desired diameter of tree skirt plus 1/2 inch (ours was 21 1/2 inches, to make a 42-inch skirt). Holding end of string at corner of gold-fabric square, draw an even, curved line from one edge of square to the other. Repeat to make a smaller center opening, using a length of string about half as wide as your tree's trunk (our string was about 3 inches). Cut out fabric along pencil lines, then open fabric and cut a slit from center opening to outer edge. Repeat with lining fabric (or use more gold fabric).