These sandals started with two small pieces of balsa wood cut into shape and painted black.
Then I made the insoles of cardboard and glued them into the balsa pieces. I took the picture before painting the other one, so you can see the shape of the cardboard and how it was glued in place.
Next, I glued silver colored leather to the insole. Usually it would have come later, but as I wasn't going to glue the edges of the uppers under the insole, this could be done at this point.
The next picture shows the rest of the leather parts in place.
Here is a closeup of the mechanism used for the ankle straps. The other end of the strap only needs a loop into which you insert the hook. The hook is bent slightly outwards to prevent it from scratching the doll's foot. This is a simple, but effective mechanism. The only difficulty is determining exactly the correct length for the strap, so that it will be possible to insert the hook, but the strap isn't left too loose.
Finally, here is a photo of the shoes on the doll's feet. The heels are made of balsa wood and covered with the same silver colored leather.