Make wearing sunscreen a habit! Your skin is like and elephant it never forgets! Men should get into the habit as well, use a mild sunscreen as a aftershave and moisturizer. It could very well save you life!
"Always wear sunscreen" is one of the most valuable pieces of advice. Even on cloudy days wear sunscreen - UVA/UVB rays can still affect you even if there is cloud cover. Protect your skin, and stay away from tanning beds!