Have a classroom discussion about the purpose of a project that will require students to work in teams. This is often more effective than creating teams before the assignment is given, so that all the students can feel a part of the assignment and begin the think about the contributions that they can make to their groups.
Break the students up into groups or allow them to divide themselves into groups. Teachers will have to decide the most effective method, based on student interaction dynamics and the type of project being worked on. Students may work better with their friends, but make sure all the groups have an even balance between those who have strength in leadership and those who may be good workers under leadership. A committed team will need to be balanced so students do not feel overshadowed by others and so everyone has the opportunity to contribute.
Create daily goal logs that each team will fill out at the start and completion of group work sessions. Group accountability is a good way to keep the students motivated to stay on track and committed to the project at hand. Each student should contribute to the log and write a short reflection of how the group work went for the day, and each should express what he wants to happen in the next work session. This goal and reflection work will keep the students committed to their team and to creating a strong finished product together.