How to prevent wrinkles on my face?

No Sun/Tabac/Xtreme: Avoiding sun and tobacco use are two of the most important things you can do to lessen the formation of wrinkles. Repetive motion will also cause wrinkles but I am not sure this can be avoided other than by use of botulinum toxin. Repeated weight gain/loss also contributes to skin laxity and wrinkling.

Avoid oxidation: The effects of aging are due to a chemical reaction called oxidation. Sun, smoking, poor diet, stress among other things further increase oxidation. Avoiding these things will help somewhat. Adopting a lifestyle that minimizes excessive oxidation will also help to a degree but father time, like gravity always wins. Some things are unavoidable.