Here is one way I package my cards for gift giving. It is the easiest way besides bagging them that I have found. I requires no extra card stock or a template.
I get paper pocket folders from the office supply store (I prefer black or white) and cut the top off by a few inches. I score an inch above the pocket and snip out small Vs along the spine and left and right edges. I fold down the flap so it will hold the contents securely in the pockets.
I add a ribbon to tie it all together and embellish the front to match the stationary inside. I also add my card for possible future orders.