Remember when 'round' and 'square' were the only nail shape option? Yeah, me either. Now, squoval, oval, almond, ballerina, stiletto, lipstick and-- most recently-- flare nails, are shape options. Flare nails, also knows as 'duck feet' nails, fan out at the tip like flared jeans and, well, duck feet. "Theyâ€™re inherently structurally unstable,â€? explains nail artist Maggie Franklin.