The basis for these shoes were plaster castings I had made some time ago. I glued the platform toe parts to cardboard soles that had 3 layers of cardboard glued in shape.
Next, I covered the sides of the toe parts with leather and filled gaps with leftover pieces to make sure that the outer soles would stay even when glued in place.
Then I covered the plaster casting heels with leather and glued them in place. Usually the heels are the last part to be glued, but I wanted to try a different method this time.
Then I covered with leather the edges that still had cardboard visible. The metal strip you can see in the photo is there to provide extra support to keep the arch in correct form. I don't use that a lot, but Piggy weighs more than smaller dolls, so some additional strength is a good idea.
For the closing mechanism I decided to try hook and eye, which turned out to be a bad idea as you can see later.
The straps are made of leather and the decorations are actually sticker strips with transparent background. Those are really easy to use for something like this. I covered the strips with glossy sealer just to be sure that nothing will fall off later.
The insoles are made of cardboard and covered with leather leaving some extra around the edges. I cut off the extra where the straps went, but in other places I turned it under the soles.
Here you can see the insoles with some sections already turned under.
The problem with hook and eye was that the end of the strap pointed to the side instead of going along the side of the foot. As I had already glued the pieces in place, I decided to fix this by cutting the hooks, pressing them flat and gluing the straps to the leather strips that held the hooks. So the result is no closing mechanism at all, but fortunately Miss Piggy's feet are different from most other dolls' feet and even shoes with fixed straps placed this high will be fine.