For my box, I sketched out a shape that would accommodate 3-inch x 5-inch index cards (finished dimensions: 3.5 inches x 5.5 inches). I assembled the box completely before attempting to cover it with the Twin Tak and onion skins.
The outside of my box looks like an abstract painting or a book covered with flower petals.
For the inside of my box, I used yellow onion skins. This detail provides an unexpected surprise upon opening.
The box closure consists of two small, 45-degree slots into which the cover flap can be inserted.