The first piece of advice is to be yourself. Confidence is more attractive to most woman more than looks. Most men put on an act to try to catch a beautiful woman, but the more natural and confident you are seems to work best. Haven't you seen some ugly men with sexy women? That is because they show more confidence in themselves than others.
I have said this in other articles that I have written is to do little things. Little things can make a big difference in a relationship. Such as buying her favorite candy all along, taking her car for an oil change, rubbing her back, I think you get the picture.
Pay her attention. When you take your woman out don't be looking at other when you are together. How to keep a woman happy is not by looking at other women trust me. So give the attention that she deserves and this will definitely make her happy.