On the Internet you can find many different techniques, drugs and advices on all sorts of things, including skin care. They may or may not work wonders for you depending on the type of skin you have. However there are some ingredients that are not exactly the best for skin care:
Although lemon is the main ingredient in all recipes, lemon can actually disrupt the pH balance of the skin and damage it in an unimaginable ways.
Many people around the world apply toothpaste on their skin, mainly against acne. It irritates the skin to the extent of causing burns or even leaving scars.
The application of hairspray will dry up acne, but it can also clog the pores and lead to irritation.
Too warm baths may end up softening of the protective layer of the skin. This can lead to moisture, and later to dryness.