I don't know what is the perfect expression of love. But everyone has their moments of pure bliss and comfort where they feel loved. So, we should make most of such moments by expressing our love in return because letting people know their place in your life, makes things beautiful and takes the bond to another level.
Some people find those moments in daylight rays and some in the silence of night, some in the warmth of bed and some in the playfulness of showers, some in the long distance calls and some in bone crushing hugs.
So, don't let go of those moments without being just with them, if you want to have them forever in your life because you never know, the person walking beside you can be equally crazier for your love.