Preventing wrinkles on forehead?

I'm only 18 and already see some wrinkles on my forehead coming. I've had a very stressful and unhappy past couple of years, so I think that may have contributed in some way. Anyway, I would like to take whatever preventative measures I can, so I would like to know if there are any skin care products, spa treatments, foods I can eat, etc. to help prevent wrinkles.