Colors and brushes used in this manicure
The two brushes I used in this manicure.
Paint your nails with two coats of your primary polish
Use a small pain brush to smudge irregular spots with your accent color. Space them as you like! These don't have to be perfect at all, the edges will be mostly covered by black in the next step.
Now smudge black polish around the accent color spots. The more irregular these edges are the better. Also, don't cover the accent spots continuously around the edges, just do two or three sides.
Cover with a quick dry top coat to smooth your design and add shine!