I can't think of a more important shift in youth ministry in the last decade than the renewed focus on exploring Christian spiritual practices with teens. In the midst of a culture of media-frenzy and over-scheduled lives, these spiritual disciplines offer a lifeline to youth to experience God as the ground of being and to explore the movement of the Spirit in simplicity and silence.
One resource that I have used repeatedly to help youth study and experience these practices is Soul Tending: Life-Forming Practices for Older Youth and Young Adults. This text, written by thirteen different authors, covers such disciplines as Honoring the Body, Fasting, Forgiveness, Lectio Divina, Testimony, Solitude, Healing Prayers, and Spiritual Friendship.
Each discipline is outlined in a format perfect for leading group discussion and exploration. The format provides opening questions, background information on the disciplines, ideas for group practices, and ways to continue the practice in the students' daily routines.
See a pdf sample from this resource here.