Shades: Jet Black and Daisy
Steps: Apply your base coat followed by two layers of "Jet Black" and apply the topcoat polish without curing. Next, draw some white freehand lines (remember: this doesn't have to be neat) with "Daisy" using a fine detail brush. The next step is to blend the two together with alcohol to give the marbled effect. Finally, cure the marbled effect followed by a topcoat to seal it all in.
Image Source: Snail and Hare