...get a bowl of water, pour little bits of all the different shades you want, it should float on the top, swirl with a toothpick or something like it and when it looks like you want on top of the water, then dip your nails through the water...probably the best thing I've ever seen.
Using any polish of your choice pour onto a flat surface, take one of those spongy eyeshadow applicators and dip into the polish, dab the polish on your nail concentrating at the tip and moving slightly upward. Repeat until you get the desired effect. Put a topcoat over the entire nail.
Dorotea the whale - Soft toy - Babies and kids - Artisan quality made in Italy