Using three different shades of nail polish and dental floss, you can create beautiful striped nails that will amaze all of your friends. First, select a light color for the base coat. Then select a darker and a brighter shade to use for the stripes.Apply a base coat of nail polish and then let that dry completely. Then, use the darker shade and apply a thin layer of polish on dental floss. Once the polish is applied, gently roll the floss from one side of the nail to the other to create a single line.