I tried a variety of boxes and packages on for size, and finally hit the jackpot with this little wooden crate. I think it came from the packaging of some fake apples. Yes, I own fake apples.
A perfect fit, but it needed some prettying up.
I found an image I wanted to use and resized it to match the dimensions of the bottom of the crate. Then I flipped the photo so it was a mirror image and printed it on inkjet iron-on transfer paper.
After that, I trimmed off the excess paper.
I found some cotton fabric I had on hand, and measured and cut a piece that would be big enough to wrap around the bottom of the crate with some excess to fold over on the inside.
I ironed out the wrinkles, centered the transfer on the fabric and followed the package instructions to iron the transfer on the fabric.
Next I peeled the paper off the transfer.
After that, I was ready to attach the fabric to the crate. I draped the fabric on the bottom of the crate, sort of like a miniature tablecloth on a tiny table.
Then I flipped the whole thing over, wrapped the fabric around the edges and began stapling the fabric to the inside of the crate, first starting with a staple in the middle of one side, then in the middle of the opposite side. (And continuing on to the third and fourth sides.)
I pulled the fabric taut and stapled the fabric on each side, working my way out from the middle staple to the corners. Next, I dealt with the corners by folding the fabric over the edge and stapling.