I personally think that most massages given by ones lover is sensual. I've been giving my S.O massages for quite a while so I should be able to give you some pointers
Set the scene first up, have a couple of candles going around the place (I only have one at the moment). What oils are you using? I make up my own concotion of essential oils, if you don't know how to make your own, get down to your local aromatherapy store and get a massage oil that is premade
A massage isn't just about rubbing a person here and there, there is a technique to it. Most importantly is how hard you massage. Harder is not always better. Start off with her lying on her front, work the back, then the legs, get her to sit up and lean back on you to do around her shoulders. Do the front of her legs and work your way up to her chest and go on from there
I'm not giving away all my secrets, best thing to do for learning to give a massage would be to pickup a book on it, I'm sure you will find that there are books on giving a sensual massage as well. I've just learnt things over the years I've been with her, what she likes and doesn't like etc.
Just enjoy it and don't get upset if she falls asleep because the massage is so relaxing
Means you're doing it right