I found you can buy ACTUAL Swarovski round, flat back crystals online, fairly inexpensively. Although, I must be honest and say...that the crystals ended up costing a little more than the shoes!! ..blush. Here's the ones we bought: Series 2028, Swarovski, round flat back, Clear colour. They measure 6mm across, and we bought 144 - that's one gross of them. This was plenty to do the toes of each shoe.
My little girl is thrilled with them. It was fairly simple to add the rhinestones. You will need, an icecream container lid (something to squeeze the glue on to as you use it), tweezers would be very handy!, toothpick, glue - we used Tarzan's Grip..more on that later! I just squeezed out a little of the glue (enough for about 3 crystals at a time, as it goes tacky so quickly), pick up a little of the glue on your toothpick, and apply to the back of a crystal, that you will be holding with tweezers in the other hand, and onto the shoe. I just worked my way across, top to bottom, left to right. Arrange a couple of lines of crystals on the shoe without glue, if that helps.
And ta-da! There you go. I thought this job might be quite challenging patience-wise - but it really wasn't too bad. And even better, Miss E has worn the shoes a couple of times already - not one Swarovski has fallen off. Hubby thought maybe a urethane bond glue would have been better? but hey, the Tarzan's grip has been fine. No playing soccer in these twinkly numbers! Cute huh?! ;)
Oh, and one more thing. Let the glue cure for a good 48 hours before wearing the shoes :)