We all do this. We buy our first foundation and concealer in our 20s and wear the same formula throughout the years. But when we are 35 the same product may not work for us According to beauty expert Janet Fernandez here are signs that you are buying the wrong make-up product. Your foundation is no match Nothing can look more unsightly than the foundation leaving a dark line at your jawline. If you find it difficult to pick the right foundation for your skin tone get any professional at the cosmetic store to find the right match for you.