Conduct a role-playing introduction exercise. Divide your ESL students into pairs and have them introduce themselves to each other. Stress the importance of a firm handshake and of making eye contact.
Conduct role-play about how to start a conversation. For example, encourage your students to ask where the other student is from and what he likes to do for fun. Tell the other student in the pair to respond appropriately with a phrase such as, "I always wanted to go there."
Take your students to see a theater performance. Encourage them to talk to native English speakers about their interpretations of the show during the intermission or at the end of the show. Tell the ESL students to observe the native speakers' facial expressions, body language and gestures and to relate them to what they're saying about the show.
Take your students on a museum tour. Tell the ESL students to listen and watch how the native English speakers interact and focus on body language, gestures and facial expressions as they observe the museum exhibits. Take similar field trips to local businesses or organizations and have the ESL students take note of the work being done and the interactions among the workers.