These shoes are a variation of one of the pairs I made for the Monster High doll. In the photo below, you can see the plaster castings of Silkstone Barbie's feet, a pair of wedge soles I have made using casting resin (these soles can be seen in the second row from left in the picture showing all cast soles), and a drawing of the insole. When the sole is ready before you start making the shoes, you need to draw the insole pattern using the sole, not the doll's foot as is normally the case.
Here are the insoles with the leather insoles glued in place and small pieces of leather glued underneath (but not yet trimmed) to guide the straps and make the toe part of the sole even. The crosses on the cardboard soles are there to help keep the right side down. As the wedge soles are uniform soles (right and left are the same), but not exactly symmetrical, it is important to make sure the cardboard soles won't turn over unnoticed before they get glued to the leather pieces.
Here are the uppers, which are almost identical to the ones I used for the Monster High doll's shoes.
The next photo shows the uppers glued in place. All that is left now is to glue the wedge soles in place, paint them and glue leather outer soles in place.
Here are the finished shoes. The reason why I painted the sides of the soles last is that the edges of the leather pieces glued underneath the insoles need to be painted as well, so they will not stick out. The leather pieces at the bottom of the wedge soles are there to cover the unevenness of the surface. As the soles are cast so that this part is in the opening of the mould, the surface is different from the other surfaces. Another solution would be sanding, but it is much easier to just glue leather outer soles in place.