Have her serenaded on Valentine's Day. You can hire a singer to surprise her with a Valentine's song, such as 'My Funny Valentine' or Martina McBride's 'Valentine'. Or, serenade her yourself and end with the proposal!
Give her a heart shaped box of chocolates, with one chocolate missing and an engagement ring in it's place. When she opens the box, get down on one knee and pop the question.
Get a box of children's Valentine cards. Put a different message in each one, such as "I want to spend the rest of my life with you". Have the last one that she opens say "Will you marry me?".
On Valentine's Day, use the little heart candies and spell out the words 'Marry Me' with them. For extra romance, only use the hearts that say 'Marry Me' on them.
Give her a beautiful heart trinket box with the ring nestled inside. Engrave your proposal or your names with the date on the top of the box. This personalized proposal will be a Valentine's surprise that she'll never forget!
Buy a card that says "To my fiance on Valentine's Day". As she opens the card, she will be surprised and then you get down on your knee and propose.
Take her out to a 5-star restaurant for dinner and have the waiter bring the ring with dessert. When the ring arrives, ask for her hand in marriage.
Give her a heart pendant necklace for Valentine's Day and then surprise her with a Valentine's Day proposal as you get down on one knee with a ring. She'll think the necklace was the only gift and then be surprised with the proposal.
Get a dozen (or even 2!) of roses and tie the ring to one of the stems. When she notices it, ask her to be your Valentine for a lifetime.
Bring her a single Valentine rose and try putting the ring inside the petals. Hand it to her carefully and as she smells the rose, she'll see the ring. Take the ring from her flowers, place it on her finger, and get down on one knee and propose.
Place roses and rose petals around the room and light candles everywhere. Create a cd of romantic Valentine music and have it playing when she comes home. Invite her to dance with you and spend the cd whispering sweet nothings in her ear as you dance. Have the last song be Martina McBride's 'Valentine' and as it ends, get down on one knee and propose.
Tell her that she's stolen your heart and ask her to keep it forever. Give her the ring -- a heart shaped diamond -- and get down on one knee and propose.
Buy several bags of candy conversation hearts and take out all of the hearts that say "marry me". Put them together in a special heart shaped candy dish and give it to her. As she starts reading the conversation hearts, get down on one knee with the ring.