This may seem like a rather silly question, but what size boxes do you usually use for your cakes? For example I remember my Wilton Instructor telling us to get a cake board 2 inches bigger than your cake to allow for borders and other decor. So if I wanted to package say a 1/4 or 1/2 sheet cake what size box should I purchase? Do you use boxes the size of the board you are using or slightly bigger?

The box size is the same as the board size. That way your cake fits nice and snug and doesn't move around while transporting.