One of the problems of youth ministry as it is conducted in the US is the lack of connection with adult Catholicism. I saw it in college campus ministry, often and especially where parishes and high schools were doing good work with young people. They would arrive on campus and many would expect the same dynamic, surprised they were asked to serve and lead in the community. Their experience, especially in schools, was that they would be serviced. The Aparecida bishops seem to be aware of this somewhat:
g) In pastoral methodologies, strive for greater harmony between the adult world and the youth world.
Big group events:
h) Bring about the participation of young people in pilgrimages on national and world youth days, with proper spiritual and missionary preparation and together with their shepherds.
Possibly more important would be the large group events conducted in regions, and even in communities that do not celebrate a weekly Sunday Mass. Pilgrimages, too, are important. The metaphor of journey, actually expressed in body and mind, can be extremely fruitful–with people of any age, actually.
For deeper examination, an English translation of the 2007 document from the Aparecida Conference.