Whenever a player leaves a game or practice, she should be bid farewell by name. Players should hear their names spoken in a friendly tone of voice often. It's music to their ears. My friends smile at me often. Many coaches act as if too much smiling is unsportsmanlike.
Coaches can communicate that they like a player perhaps more easily by smiling than any other way.
Humor that does not make fun of someone is something that typically only goes on between people that like and care about each other. Friendly humor causes people to enjoy each other's company, something that can be important in a stressful setting such as an athletic team. Eye contact of a friendly nature communicates caring. Touching kids can be a controversial issue in a time when so much sexual abuse of kids is being uncovered. People simply do not chose to touch people they don't like.