None at all...
Seriously, the human race has done without skin care products for millions of years, 90% of the worlds people, the ones who happen to live in less fortunate parts of the world still do without it, and even 90% (more?) of the male population in developed countries do without it. Unless you have a serious allergy which requires prescription medicine, you can really do without skin care products altogether, although the marketing people at Boots and the like want you to believe otherwise.