Married 26 years, my wife and I are 51, and we've renewed our love (and lust) in the last 5 years.
#1: Take your wife out on a date every Friday night.
#2: Love is a verb. I started turning things around when I made a commitment: I will make sure that my wife knows I love her every day. Not just tell her - make sure she knows it.
#4: Have a great sense of humor.
#5: Do whatever it takes to arouse and share pleasure within safe limits. I won't go into details, but fantasy, touch, there are plenty of safe ways to get spicy.