5 Ways to Lengthen Lashes Naturally: Wash an old mascara or nail polish container fill with: 1/4 of the container with Castor Oil, 1/2 Vitamin E Oil, 1/4 Aloe Vera Gel. Mix the together as well as you can with your mascara wand, and apply a light layer to lashes brows every night, careful not to get too close to eye avoid using too much that could drip inside your eye. Castor oil thickens your lashes while aloe vera gel lengthens. Vitamin E accelerates length. Give it a month for results.