Take a light silver sparkly varnish.

Paint half the nail in the light silver and repeat on each nail on one hand making sure that you paint on either the outside or inside sides of each nail. Repeat on the other hand. Apply 2-3 coats depending on the transparency of the varnish.

Take a dark silver polish.

Paint the remaining half of each nails with the darker polish. Apply 2-3 as before.

Take a black nail art pen or a very fine brush and some black varnish. You will be using blobs the size of the blob shown on the nail pen. Practice a few times to get the right amount of varnish.

Starting at the bottem of the nails apply small blobs of black varnish up the 'seam' of the two silver. Apply these approx. 1mm apart. Do not rush or make you blobs too large or you may end up with them merging into one another.

Apply blobs of black varnish all the way up the length of the nail on each nail.

Take a clear nail varnish.

Cover the nail with a layer or two of clear varnish, wait until the nails near enough dry before you d this otherwise you might drag the blobs.

And wallah you are done (just wait for them to dry!).