I created this mani a couple of weeks ago now after seeing a few versions around the blogosphere, and I really liked how they came out. I couldn't find any tutorials that I was happy with and I ended up using an amalgamation one few different ones, so I thought I would add another into the mix, showing how I created mine.
Start with a black base. I used Barry M black, and then cut a small piece of makeup sponge to use for the design. Pour a few drops of silver nail polish, I used Barry M silver foil effects, onto some plastic, and dip the sponge into it. Sponge random lines and swirls across the black
I put glitter over the black on my index finger and thumb, but I would actually recommend putting it on all of your fingers, and omitting it at the end, to give more depth. Next you need to take a light greenish polish, I used OPI Mermaids Tears and sponge that around the silver.
After you have done that, you might need to cut a new pice of sponge, depending on how big the piece you are using is, as you don't want the pink to go everywhere. Taking a pink polish, I used NYC fashion ave fushcia, dab a small amount through the middle of your silver bits, and around the edges of your nails, making sure you don't apply too much, or completely cover the silver.
Next you need to get a dark purple, I used NYC expert last in midnight amethyst, and use it to soften any areas of pink meeting black. You can also use a nail art pen or small brush to add small clusters of white dots for stars, or use a glitter topcoat (or both!)
Finish with a clear topcoat and clean up around your nails with cotton buds soaked in acetone. Marvel at the constellations on your fingers!