First things first! Ruby Slippers, of course. I couldn't start with anything else but shoes - love'em!
OK. You'll need Spray Paint, Craft Glue, Glitter and any plastic shoe shaped object:)
In my case, I've used my leftovers after our Home Production of Cinderella Story.
I bought them in local discount craft store 25 cents each. They are 3" long.
I've used Spray Paint by Krylon in Red Pepper Color. I didn't do any prep work - no sanding, no primer, nothing. It worked well... If you are using any other paint and you don't want to mess up the final result, you should try it first.
After paint had been dry, it took 1 hour, just because in some areas I sprayed too much :)
I covered the outside of the shoe with Martha Stewart Glittering Glue (leftover from X-mas crafts). Note: The glue is great, the applicator that comes with it awful - I am always using my own brush - it will save you your time and product.
You can use any other craft glue, I am sure it will work just fine. I am not spending any $$$ I am using what I have, do the same if you can - it's more fun.
While the glue is fresh it's time to glitter. I have used, again Martha's Garnet Glitter, but you are free to use whatever glitter you have (I've experimented with different glitters from different companies but it seems that Martha knows a . Shake any access off and let you Ruby Slippers dry.
Now, you are ready to follow the Yellow Brick Road.