In the writing center, children can write a letter to a friend and draw a picture. Children love to draw concepts they cannot fully express. Many kindergarten teachers encourage developmental spelling in which children attempt to write by putting down the sounds they hear. This activity encourages children to think about the concept of friendship and gives them a chance to express their feelings as well as practice recording sounds they hear.
In the drama center, give children pictures of a scene that can be interpreted as a friendly action or a non-friendly action and and let them act out the story. You will need some props for this so children can take on different characters. Aprons, hats, play swords and shields, big shirts, men's ties, baby dolls, play food and similar items will help the young actors express what actions are friendly and not-so-friendly.
Stock the reading center, library or reading corner with books about friendship. Good books for kindergartners include "Frog and Toad are Friends" by Arnold Lobel, "The Red Book" by Barbara Lehman, "Corduroy" by Don Freeman and "Lyle, Lyle, Crocodile" by Bernard Waber. You can find books at many reading levels that would be appropriate for this center. "The Red Book," in fact, is wordless.
Friendship is a popular topic in songs for kindergartners. Songs for Teaching lists many songs from "1-2-3 Do You Like Me?" by Kathy Bell to "ZooDeeAy" by Music with Mar as songs with friendship themes suitable for the kindergarten set. At the listening center, provide these songs and a set of earphones to reinforce the concept of friendship.