Hi girls - it's actually really quite easy to do these nails and they do look cool!! About 7 years ago CND did a shot using the same type of 'arty bits'.. Basically, you use Perfect Clear and have a mixed pot of X,Y,Z next to you...once you have created your bead - squish it GENTLY into your mix and place upside down (so the mix is on the nail and the upside of Perfect Clear is there to work with) - just push into place creating your smile and add zone 2 & 3 in Perfect pink!! Finish as normal and this will give you this look - if you think about it, you could use ANYTHING!!! 8)
For those that love to sculpt (like me, he he), do the layering thingy as you usually would with your white, and follow what sam said,
When you do your first bead (bottom bead), use gold glitters and when you do your second bead (top bead), use silver glitters, (or vice versa). So what you get is one colour on top and another colour on the underside. But allow your first bead to cure for a minute first so your glitters dont bleed into eachother.