Celebrate "The Wizard of Oz" when you're trick-or-treating.
Wig: See the basic wig instructions. Use one skein of medium-weight yarn to make a wig with hair about 25 inches long. Divide the hair along the center part and make loose, low, side braids, tying the ends with a piece of yarn, then with blue ribbon.
Dress: Outline the shape of Dorothy's dress with white duct tape on the back of blue gingham fabric, as shown. The rectangle needs to be wide enough to wrap around your child with a few inches of overlap, and tall enough to reach from chest to knee. Mark and cut out the interior of the neck strap and make sure it's big enough to fit over your child's head before cutting the outer edge of the strap. Attach the center of a 62-inch length of 1-1/2-inch ribbon to the front of the chest with double-sided tape. Have your child wear the dress over a white shirt and skirt. Tie the ribbon in a bow in back.
Round out the costume with plain canvas shoes colored with red acrylic paint and glitter paint, and a candy-gathering basket complete with plush Toto.