Right sides together, stitch two tongue/toe pieces together except not around the toe curved edge. Turn.
Right sides together, stitch two sides together with a piece of interfacing between them. Leave the long bottom open. Turn. Stitch one ribbon or shoestring 6" long to each of the sides, as pictured.
The second photo is of a top sewn together. Place two sides on the tongue/toe piece, as pictured. The two side pieces should slightly overlap the tongue/toe piece (be on top a bit). Stitch around the entire outer edges of the whole shoe top. Fold the whole shoe top so that the sides are right sides together. Stitch the center back seam of the shoe top.
The last photo is pinning the fabric sole to a shoe, right sides together. Stitch two soles wrong sides together. Right sides together, pin in a sole to a shoe. Stitch around the entire shoe edge, careful to not catch the ribbons or shoestrings in the stitching. Turn the shoe. Trim the two pieces of cardboard and place one inside each shoe. Then, the saddle oxfords are all ready for the dolly to wear.
There are many possibilities for the shoe color and fabrics: solids, prints, whatever you like. Have you ever made any doll shoes? Prim blessings,