What you need:
Craft glue (I use PVA or tacky craft glue)
Shoes - heels or flats
Clear spray craft varnish (Crystal Kote etc)
Lots of newspaper
1. Cover your whole work surface area in news paper. Stuff the shoes with newspaper too.
2. Working in sections, paint on the glue thickly.
3. Glitter each section as you go. Once whole shoe is completely covered in glitter allow to dry.
4. Once dry (normally a couple of hours) take outside and sit on more newspaper. Completely saturate the shoes in the spray varnish to help keep the glitter on.
5. Add to suitably colourful costume and marvel at you glitter shoes. Ta Da!