Do romantic stuff like sending a personal letter, or some flowers when the time is right. It is also a good idea to keep negative feelings like jealousy outside of the relationship.
Romance loses its power when you keep a score of what all you have given and received. This is not a game.
It is good to ask yourself how much you love your partner, and what life would look like without this person in it. This exercise snaps you back to reality if your love is real.
Keep apologizing for all your mistakes. Find new, creative ways to apologize and mean it. Say sorry even if you think you are right.