There are a few simple rules any guy can follow to make sure his significant other has a great Valentine's Day:
This may sound silly, but do what is needed to make sure you don't forget Valentine's Day. Set calendar reminders in your phone, tablet, email, etc. These should be right next to your anniversary and her birthday. For an extra shot of surprise, don't forget, but pretend you did then wow her with something special.
Don't buy generic gifts
I'm not suggesting that flowers, jewelry and chocolate are taboo I am suggesting that they should mean something. If you get flowers make sure they have emotional significance. For example, her favorite flower, or a flower she mentioned was beautiful on a walk in the park, etc. Jewelry follows the same rules; make sure it's something that has special significance in your relationship.
Make it special
If you go on romantic walks in the park on a regular basis, do something different for Valentine's Day. If you frequent fancy restaurants, don't do this for Valentine's Day. You don't have to spend tons of money, doing something out of the ordinary and being just a little spontaneous will go a long way.
Give her the chance to feel beautiful
Again, you don't have to go to an ultra-expensive restaurant for her to get dressed up. You could do a formal picnic, depending on the weather. Take her somewhere where people will be able to see how proud you are of her and how beautiful you think she looks. Give her time to get ready and spend the extra time she wants on her hair and makeup. Sometimes, it's the preparation that makes something special.
Do something to help her
One of the best ways my husband shows he loves me is he will do something to show he acknowledges how hard I work; he wants to help me out and give me a break. Coming home to the dishes being cleaned, or the laundry done, folded and put away is one of the best gifts any wife could ever get.
You know your lovely lady better than just about anyone, so do something that will make her smile because she knows you did it just for her and because you know her so well. Be tender, sensitive, and loving. Overall, just be the man she fell in love with because you are what makes her happy.