After a while you may think you know how to please your partner in every way, but this is very rarely true. There is always something you haven’t tried, and there is bound to be something one of you always does that could be done differently.
To combat this for better sex, have a lesson session in which you don’t think you know it all, and are at each other’s mercy as teacher. Talk about things you haven’t tried, but would like to, then choose one suggestion from each partner, and get down and dirty. We often get caught thinking we know what our partners like, and after a while it becomes “the way it’s done.” Lose this myth and put yourself in the student’s chair for a while for better sex you won’t regret.