I have done this before and it a great thing to try out. I will be doing it later today and will update this with pictures of how they turned out!
What You Will Need:
Nail polishes – Whatever creates your most desirable color combination.
Small plastic container/cup - Note: container will get ruined during the process.
Water – Room temperature is optimal.
Wooden sticks – Opt for wooden cuticle sticks.
Newspapers/Paper towel – For spills and other messes.
Scotch tape – To wrap the nail and help place the marble design.
Step 1: Tape up the three sides that surround your nail so that you do not get polish all over your skin.
Step 2: After filling up your cup with water, take your nail polishes and lightly drop a tiny dot of each color into the water so that each drop is placed on top of the other after it spreads.
Step 3: Take your cuticle stick and drag it through the polish from the outside to the middle creating a unique design of your choice.
Step 4: Dip one tapped finger nail into water and keep it there, as the polish will adhere to your nail.
Step 5: Remove your finger from the water/polish mixture, and use a cuticle stick to remove remaining polish out of water. Repeat the process on remaining fingers.
Step 6: Let dry and finish your nails with a good clear top coat to seal the deal.
And that is all there is to it!!
(I do not have a clear coat over this, and i re-did the thumb as it was too dark, as you can see in the first picture)