I purchased a plain storage box similar to the one above at a local shop like Walmart or Target and turned it into a cow print box for my daughter's room (that's what she was into at the time).
First I got a piece of foam cut the size of the top of the box, next I got some material to cover the lid (with the foam as well).
Using a staple gun I fastened the material to the top and she had a storage box seat to place under her window.
We were planning on painting the box as well, but she couldn't decide what color she wanted so we've left it plain.
As I said previously there are lots of cupcake fabrics on the market to choose from, alternatively you could get some fluffy material in the room's dominant color and just use that with a cupcake throw pillow resting on top as well.