I haven't made shoes for Barbie (except for California Girl Barbie), because her feet are so small, but I decided to try and see how hard it really is. I eliminated some steps from the process of making larger shoes, so these shoes don't have leather insoles, just three layers of cardboard glued in shape. The ribbon I used was the narrowest one from a set that had four different kinds of black and white ribbons.
I was making the shoes using the plaster castings for Silkstone Barbie feet, so I decided to add ankle straps. That way, the shoes can be used on other Barbies as well. The ring between the two pieces of strap is actually thin rubber band. On one piece of ribbon, I made a loop where the rubber band can move freely. On the other piece, the ends of the rubber band are glued in place and the end of the ribbon glued on top of them (so it is like another loop, only glued shut). I used rubber band so the strap would stretch a bit, if necessary, when putting the shoes on the doll's feet.
Here you can see all the straps glued in place. You can make the ankle strap a tight fit, but do not stretch the rubber band when gluing the straps in place.
The heels are tiny bits of balsa wood covered with leather.
Here are the finished shoes. The outer soles are made of the same leather I used for the heels.
I was surprised to find out that these were not as difficult to make as I had imagined. Leaving the separate insole out helped keeping the edges neat and it occurred to me later that using different colored cardboards for the different layers of the soles could be a good idea.