From:

Button Ornaments

The basic technique for all the ornaments is the same. Bend a pipe cleaner in
half and twist once at the top for a loop. Slide buttons over pipe cleaner ends,
slipping one end into each hole (if the button has four holes, use two diagonal
ones). Use larger buttons for bellies and hat brims. When finished, twist ends of
pipe cleaner to secure, and trim. For reindeer legs and antlers and for Santa's
arms, bend 2-inch pieces of pipe cleaner in half, slip on between buttons, and
twist. Glue on felt for Santa's beard and the snowman's nose. To hang the
reindeer, loop a thread around its middle and tie.