Smile at each other, smile at your wife, smile at your husband, smile at your children, smile at each other - it doesn't matter who it is - and that will help you to grow up in greater love for each other.
Smile brings joy not only to oneself, but to one's surrounding as well. Prophet Mohammed pbuh says: "Smiling at your brothers face is as charity". And there is an Arabic proverb which says: "Smile and life will smile at you".