Be aware of reflected light. Sitting in the shade is no guarantee of protection, especially around water. Don't get lazy on cloudy days. As much as 80 percent of the sun's radiation makes it through the clouds. Examine skin regularly.
Early detection is critical.
Keep an eye out for unusual growths, itchy patches, sores that won't heal and changes in moles or colored areas. Avoid sunlamps and tanning beds. And like all things in parenting, set a good example.