Lead: the quantity of skin product is increasing every year. How to preserve them is also impact our skin directly.
Dustproof- the cosmetics will touch our skin directly. Except prevent the qualitative change, it also need prevent dust.
Prevent water and sunshine- its material are almost chemical synthesis and even the natural material also need the chemical processing. Water and sunshine is easy to cause the chemical change of cosmetic.
Regular review- the preserve time of normal cosmetics generally has 3-5 years. But, it is only 1-2 year after opening. So, it is best to write down the unpacking date. 
Refrigerator to preserve- if you have the habit of preserve cosmetic in the refrigerator, don't change once you do. Otherwise, it will destroy the composition.
Clean make-up tools regularly- the make-up tool such as the brush, puff, eye brush always touch skin and cosmetic directly and easy to take oil or dust on the skin into cosmetic. So, we have to clean them regularly.
Packaging processing- a lot of small bottles or small cans on the market are used for packaging generally. But, if some cosmetic has leave a little, we can change them into small bottle for save space.