Dab a cloth with some acetone nail polish remover. Rub gently at the stain to remove as much of the polish as possible. This solution would be best for treating an immediate nail polish spill.
Scrape a dried nail polish stain with a plastic knife. Be gentle with the knife, lifting away pieces of the hardened stain. Rub the stain with hot water on a cloth to help ease the nail polish away.
Scrub any stain remnants with a 0000-grade fine steel wool scrubbing pad. Scrub gently on wooden cabinets in particular to avoid damage since steel wool is abrasive. Use the hot water and cloth to work away the last of the stain.
Cover the area with a wood touch-up product if you remove any of the wood finish in the process.