Sally Hansen Ahead of the Curve Sapphire File
Unlike cardboard, this metal version is durable, won’t fray nails, and can be cleaned with soap and water. The concave center lets you angle it under tips to create a more rounded shape.
To buy: $4, ulta.com.
Featured February 2013
For even more manicure must-haves, see our round-up of the best nail tools.