Communication is a big thing in any marriage.
Marriage isn't 50/50, it is 100/100 on both people's part.
A good book that helped me and my wife is the "Five Love Languages". People understand love in different ways and if you aren't speaking their language, then it can lead to trouble. For example, my wife values "acts of service" as her primary love language. It doesn't matter how much "words of affirmation" I give her or how many gifts I buy her. What does matter is the things I do for her that she knows that I love her. If I didn't know that I would be focusing on the wrong thing and not meeting her needs.
One of the other things is setting aside a "date night" and date each other just like when you first met. Sometimes we won't even go out, but just plan a night together at home with a special meal, movie or something we enjoy.
"God gave you a brain, and it annoys Him greatly when you choose not to use it."