I'm wondering why you've decided to do this. Is there trouble brewing in your relationship and you're concerned that she may be growing away from you? Y'all should be letting your wives know all the time that you love and appreciate them.
Depending on the woman, sometimes all the actions described above just make her feel that you only want to get laid. And it may backfire on you.
If your intent is sincere, then sit down with paper and pen and write her a letter. Tell her about the things that made you fall in love with her and the things that make you love and appreciate her still. Make the letter long and meaningful. Put it in an envelope and then leave it where she can find it and read it ALONE. Let her be the first one to say something after she has read it. If she doesn't say much, or says nothing........