This is a pair of second hand 70s or so shoes. They have pretty much the same shape as 18th century mules, though the heel won't be accurate. If you want to try and alter it, that's up to you, I won't because I've had bad experiences trying to do so. As you can see, these shoes had straps and I cut them.
And glue it; I chose glue because the shoes' fabric is too thick to sew on it.
Add a bow maybe?
These shoes fabrics were brocade fabrics normally, but these tend to be expensive. If you want to save money I recommend glueing or ironing these flowery decorations that may not be brocade but add some texture to the smooth shoe.