This is an old worship leaders’ method, and it’s very effective. It’s sort of a combination of personal prayer and collective Praise & Worship.During a reflective or prayerful time get the young people singing a worship song. Preferably the sort of song that’s fairly repetitive. At key points in the song, just leave a long paus between verses, while the guitarist keeps playing, an get the young people to close their eyes and invite them to pray. You might want to give them something specific to talk to God about. Maybe something relating to the song.This, of course, requires a guitarist, but if you have one, it”s great!