Having traveled over a million miles in my life (with over half being in a carry-on), I've learned a thing or two about paring down my beauty bag to just the essentials. I follow two rules that help keep me balanced: pack my lifesaving items, and swap the items I can. I will never travel without my favorite face oil, but have no problem using a cleansing towelette instead of makeup remover or applying the hotel-provided lotion instead of my own. These nine beauty products are the ones I never leave home without. They keep my skin clear, my hair bouncy, and my sanity intact.