I red-glittered these shoes for my Halloween costume. (It's not Dorothy, though!) They were originally the color and pattern of that patch in the instep. I looked up various how-tos online, and used a combined method.
1. I sanded the surface of the shoes to help the glue stick. This helped a lot, and I should have done it more.
2. I mixed school glue with water, to the consistency of dish soap, and then added glitter. I discovered you want a lot of glitter in there, so much that it thickens the mixture.
3. Then, I applied it with a paintbrush. It took about five coats to cover the surface thoroughly. Once dry, the glitter has stayed on really well.
I'll post more on this costume. Embroidery on knitted fabric is hard, but it's coming along!