Tokens can be anything that is readily available.  They should be something that is easy to see and not blend in with the rest of the classroom supplies.  A teacher can use the same tokens for each student or use different tokens for different students.  Regardless of what is used as a token, the goal is to help students learn new appropriate skills and behaviors.  The rewards should be tangible and readily accessible for the teacher, yet useful or enjoyable for the student.  Each student will most likely have their own token system.  In order to enhance student ownership in the process, the student should be asked for examples of specific goals of the program.  This is also a system that can be implemented in the home in conjunction with school goals or just focusing on goals at home.