How can I prevent hair loss?

As I get older, I become increasingly worried about hair loss. Looking at my friends around me, it seems like more than half of them have started experiencing hair loss. Seeing friends who have already experienced significant hair loss made me think that I should prepare something in advance. The first things that come to mind are using anti-hair loss shampoo and eating foods that are good for preventing hair loss. Is there anything else I should pay attention to in order to prevent hair loss? I would like to know.