1. Pay attention to the wording of the question and be honest.
Some applications will ask about any disciplinary violation for which you have been found responsible, while others will only ask for those which have resulted in probation, suspension, dismissal, or expulsion. If you check the “No” box when the answer is truly “Yes,” you are likely to get caught. Somewhere in your guidance counselor's report, with your transcript, or in teacher recommendations, the situation may be mentioned. Your application would then be immediately rejected.
2. Show an understanding of what you did and why it was a mistake.
The explanation should be more sophisticated than “I wish I hadn't gotten caught.” Provide a narrative of what happened and what was going through your mind at the time and in the days that followed. What factors played a role in the decision(s) that you made?
3. Make it clear that you learned something.
Don't bother promising not to make the same mistake once you're a student at ___ University. Instead, think about the broader implications of the issue at hand. How has it impacted your understanding of yourself, of your peers, and of society as a whole? What do you see as your role in the world, and how did this experience help to shape that?
With some careful thought and consideration, and an honest and open approach, you can turn this potentially negative question on the application into a deep exploration of your experience as a well-rounded human being. If you find yourself having to write this part of the application, take it seriously and show the admissions officers how you became the mature and experienced person you are today.