Sunscreen
The best sunscreen is the sunscreen you will wear! Ideally, your sunscreen should be broad spectrum and have an SPF of 30 or higher. Mineral sunscreens (zinc oxide and titanium dioxide) offer broader protection than chemical sunscreens, however both are considered acceptable. Apply one ounce of sunscreen to your face and body. Sunscreen should be applied to skin every two hours.
Sun Protective Clothing
Clothing brands with UPF in them (cotton only has a UPF of 5!):
Nicotinamide
Nicotinamide is an oral, over-the-counter supplement that has been shown to decrease the incidence of non-melanoma skin cancer by 23%. 500 mg should be taken by mouth twice daily. It has very few known side effects. Ask your dermatologist and primary care physician before starting.
Preventative Treatments
Your general dermatologist may recommend photodynamic therapy or topical chemotherapy (such as 5-fluorouracil cream) to treat actinic keratoses (pre-cancers) and decrease the rate of skin cancer formation.