Pushing a mascara brush in and out of that little tube forces air into the container, drying out your mascara long before you've actually run out of product. You can extend the life of your mascara -- as long as the product hasn't expired -- with a few drops of water. Put a few drops of water onto the mascara brush and insert it into the tube, moving it in a circular motion to stir. The mascara will re-hydrate and you'll get a few more months out of your product.
