Keep it in tune with the times, but don't write with the specific purpose of trying to create a hit. If you're doing it strictly to make money, you're crazy. There are easier ways to make money.
“In my grandfather's lab, scientists did independent research, and peers reviewed and commented on its merits. Politics, he taught me, had no place in the scientific process.”
“I married a woman who is much better than me, I'm very fortunate to be with her and I know I'll be happy with her the rest of my life.”