1. THOU SHALT NOT believe expensive cosmetics are better than inexpensive cosmetics.
2. THOU SHALT NOT believe there is any such thing as a natural cosmetic (or that natural means better).
3. THOU SHALT NOT believe in miracle ingredients that can cure skin-care woes.
4. THOU SHALT NOT covet thy neighbour's perfect skin (or believe her perfect skin came from a particular product or cosmetics line; skin is more complicated than that.)
5. THOU SHALT NOT believe everything a cosmetics salesperson tells you.
6. THOU SHALT NOT believe in the existence of anti-wrinkle, firming, toning, lifting, or filling-in creams, lotions, or masks that can permanently erase wrinkles.
7. THOU SHALT NOT be seduced by every new promotion, new product, or new product line that the cosmetics industry creates.
8. THOU SHALT NOT get a tan; sun is your enemy, not your friend; it is the primary reason that skin wrinkles and develops skin cancer (and it isn't just about getting a sunburn - turning the skin brown is equally as damaging when done on a regular basis).
9. THOU SHALT NOT buy a cellulite cream, nor shalt thou assume it's possible to dissolve fat from the outside in, because you absolutely cannot. If these products worked, who would have cellulite?
10. THOU SHALT NOT see picutres of pubescent, anorexic models (who spend two hours getting their hair and makeup done and another two hours posing while the photographer and a corps of assistants determine the most flattering lighting, after which the resulting pciture goes through a battery of digitally enhanced touch-ups and adjustments) and believe you will get the same (or even similar) results from using the products being advertised. That is, unless you happen to be pubescent, anorexic, and a model and can somehow stay in the right lighting all the time.
Source: "The Original Beauty Bible" -- Unparalleled Information for Beautiful and Younger Skin at Any Age written by Paula Begoun