We were thinking about all the money a gal spends on make-up and grooming products. You know: the Sephora binge and shame jaunts; the Duane Reade/CVS/Walgreen hair accessory pick-me-up-basket-fill-ups; the Avon lady calling and you buying all she’s selling visits. When it occurred to us the biggest error most of us make when applying make-up...