An advantage of using picture books to teach inferences is that the facial expressions of the characters are visible to everyone. Before reading a given page, ask students what they think the characters are thinking or feeling, given what they know of the story thus far and the facial expressions of the characters. Be sure to follow up any answer with a clarifying question like, "Why do you think that is what the character is thinking?"
The setting is also clear to everyone when reading a picture book. Using the setting to make inferences can inspire some interesting conversations about how our experiences shape our inferences. Given a setting that is mostly buildings may make some students infer that the character(s) involved must feel uneasy, while others will infer excitement from the same setting. Be sure to include a discussion of taking in clues from the picture as a whole when confronted with these seemingly contradictory inferences.
Having students pantomime feelings or ideas is an active way to work into a discussion about inferences. Split students into groups of three or four and give each group a situation or an emotion that they will have to act out without using words. After a few minutes of preparation, each group will perform while the rest of the class attempts to infer what they are trying to convey. After each performance, lead a brief discussion about what made the students successful (or not) at the inference activity.
Encourage students to bring in photographs of them or their families "in action." Each day, choose two or three students to show the class their pictures without giving any details about the event taking place. Ask the class to infer how each person in the picture is feeling, where they are, and what event they might be participating in. This activity is in line with the picture book concept, but it allows students some ownership and gives them the opportunity to learn about each other while learning about inferences.