The ministry of presence is one of the greatest things a pastor can do for his or her school. The sad reality is that few pastors take the time to get involved in the schools that their youth attend. Relationships are the context from which ministry takes place. Therefore, a pastor must practice the ministry of presence.
Start by showing up at your school regularly. Learn the names of the students, show up for lunchtime, and just hang out with them. Ask about their day, how the school is going, likes and dislikes, etc. As you get to know them, you will learn what is important to them. You will find that as you do this you will win their confidence, and the relationships that are built in those settings will give you influence and allow you to speak truth into their lives.