Yes, you can be an adult and indulge in glittery polish. Nail Technician Patricia Yankee explains how in InStyle's November 2011 issue.
To get a subtle sparkle, apply a polish with fine glitter particles. Then paint over it with a sheer, neutral shade to tone it down.
To go glitzier, paint nails in your favorite shade. Then trace over just the tips with glitter polish.
To go all out, pick a formula with big pieces of multicolored glitter and bling it on!
InStyle recommends Nicole by OPI's Follow Me on Glitter, Pop Beauty's Nail Glam in Confetti Glitz, and Revlon's nail enamel in Blue Mosaic.