I read "The 5 Love Languages" by Gary Chapman about a year ago. Although I believe he has some good points about psychology of how we feel loved, I do not recommend this book. I think that a lot of what he says encourages people to stay in emotionally abusive households. That said, his structure on how we express and feel love is very interesting, so I'll summarize it here:
1) Words of Affirmation - Saying nice things, complements, I love you
2) Acts of Service - Doing work around the house or running errands for the other person
3) Giving Gifts - self explanatory
4) Physical Touch - self explanatory
5) Quality Time - spending undivided attention together
Simply put, figure out what you and your partner do and need to feel loved and try to do more of that. I am very much a "Quality Time" person. I feel loved and appreciated when I get time doing something with someone. My husband is acts of service. He feel loved when I do chores and run errands for him. Figuring this out has greatly increased how we feel and helped us explain how we are feeling to each other.