Damned if you do, damned if you don't - use sunscreen to protect yourself but then you block out UVB rays which help stop cancer.
The only way to keep an eye on your skin is to have it checked regularly.
I pay around $130 to get half naked and have some bloke with extra strong glasses look all over my body for any moles that are particularly susceptible. I am, thankfully (well some might not think so lol), clear for another year (I am heavily freckled and have several moles and have skin that goes so pale I am seethrough lol).
I use this mob
Sunspot Skin Cancer Clinic
but there are plenty of others!
Do it - your life is worth $130 a year
btw they aren't militaristic - I actually went in with sunburn after the doggy playdate and the doc who owns the clinics said that it wasn't too bad lol