How i added rhinestones to my Voi shoes, very cheap and easy.
Grab what you need:
Rhinestones (i used 3mm ones for these shoes which i bought from eBay for less than £2 for 1000 gems)
Super glue (the gems wernt put onto fabric so i wasnt worried about spillage onto fabric they were put onto acrylic paint, if you are putting the gems onto fabric i would get a proper glue for fabric as when the super glue hits fabric it gives a look that its always wet even when dry)
I only done one rhinestone at a time as the glue dries very quickly, i put them onto the middle of my stars, if you dont have a similar design on your shoes you could add them in a mixed way on the section you want.
Then your done!
When i get some proper fabric glue i am planning on doing the front toe bit with the same colour gems.