Can anyone help me figure out a way to make a buckle for this shoe? I am going to put glittery disco dust or glitter to make it sparkle but Im not sure how to attach it or make it.

You can make it out of any medium - Fondant (add tylose or gum-tex to help it harden,) modeling choclate, gumpaste... And you can attach fondant with water or "sugar glue" (watered down corn syrup) or if you're using modeling chocolate, you can use regular melted chocolate to glue it. HTH!