Martha Stewart Living, December 2011
Start by tying a length of colored yarn to a pushpin at the bottom of the board, then zigzag the string upward, wrapping it around a pin at the end of each "bough."
Knot the yarn to a pin at the top to finish.
Hang cards over yarn.
The invasion happens every December: First the entry console is overtaken, then the mantel, by a display of holiday cards. But why not give the loveliest tidings their due with a dedicated space on a bulletin board, strung up to resemble a Christmas tree?