For lash extensions, you always want to avoid any products with oils in them as they can break down the adhesive used and cause lashes to fall prematurely. If you must wear mascara in between fills if you let it go too long, do not apply to the root. For eyeliner, it’s best to use a powder eyeshadow mixed with water and apply with an angle brush. For lash lift, you can treat your lashes as normal. Make sure you clean them!