It is so great to hear someone being conscious and intentional about skin cancer prevention. Thank-you for asking this question! The fact is that you need to take as many precautions as you can in order to prevent this, bearing in mind that some people are more predisposed to this than others.
Some helpful tips:
1) Use a good SPF everyday and apply twice a day (morning and mid-day) on all exposed areas – any areas that are not covered with clothing.
2) Use a good antioxidant serum every morning (under your SPF) – Something like Skin Ceuticals CE Ferulic serum.
3) Take good oral antioxidants, something like Ovelle from Lamelle or Heliocare capsules.
4) Wear sunglasses when you’re driving or outside.
5) Wear a hat if you’re outdoors.
6) Try and limit your exposure time during peak times.