Gather students and discuss what the term self-control means. Use a definition that is easy to understand for kindergartners such as "Self-control means that you sometime have to make yourself stop doing something or knowing when you have had enough of something."
Explain to the class that you will be using a three strikes and you are out rule to learn self-control in the classroom. Show the students the stack of note cards. Explain that every time a student has to be told "No" due to a lack of self-control, the student will be given a card. Once three cards are received, all for not exercising self-control, one privilege is suspended. For example, if you have to tell a student three times not to get out of their seat during work time, they receive three cards and skip the next recess.
Use daily occurrences to further reiterate self-control. For example, every time a child goes to do something such as hoard all the blue crayons, explain to the child that using self-control means you can use one blue crayon at a time and allow the other children to use the rest. Keep stressing the importance of self-control as a way to be fair to others; and use the concept of treat others as you would like to be treated.