What is the best way to prevent against skin cancer?

Keep out: Of tannng booths and direct, long exposure to sun' s rays. Sun screens may help, but not "the best way" to prevent; augents a compromised way.

Sunscreen: Using sunscreen and clothing to block the uv radiation from the sun is the best method. Also to know your risk of developing skin cancer and seeing a dermatologist if your are at risk for regular skin checks.

UV Protection: There are many factors that causes skin cancer-- some we can control and some we can't (like our genes, being fair skin). It is now well known that uv radiation (especially from the sun and tanning booths) are one of the major causes of skin cancer. So it's important to reduce your exposure-- such as avoiding tanning beds, covering up and wearing sunscreen, and avoiding strong midday sun.