We've got to admit: we don't really own a proper slip. We're not sure why not, either. We used to love how feminine and graceful our moms looked walking around in hose, heels and her slips. Even though we swear by our Spanx, we should invest in a few slips for wearing under our more dressy attire, starting with the Avec Toi Slip ($148). It's high quality and so lovely, too. Hopefully, we'll have it for years to come!