Honestly, I find that this is not a complicated science. Women want to know they are loved and why they are loved. So, simple things work best: doing the dishes, buying her flowers, telling her why I married her, telling her why I still love her, coming home with simple surprises (so that she knows I was thinking about her), etc. 

Paul writes that we are to love our wives as Christ loved the church, which requires self-sacrifice of the Husband for the HOLINESS of the Beloved. One thing that stuck out to me at Matt's wedding was in his vows when he said that he promises to love Andrea even when he's tired. That's what is toughest for me, because that is when I want to run away, relax, and read to my introverted self. It is then when I am really challenged to "give myelf up for her."

Nonetheless, we simply must try. I find that efforts are more important than the particular product. That is, it's not so much what they are given, but the thought behind the gesture. 

And for you non-married men out there, I find that, psychologically, this does become a discipline once you get married. Before marriage it just flowed out of me. After marriage...not so much.

Kevin