I am appalled at the existing low standards of some in our country who assume positions of Christian leadership, including youth ministry. It is as though intellect and religion are viewed as uncomfortable acquaintances, and that eagerness and personality are more critical to an appointment in youth ministry. As I encounter European youth ministers, for example, there is a keener sense that they can think, read, articulate and write with an informed demeanor. This is obviously not the favorable case for many in North America. You can't teach someone to love kids.
Passion is the most important criteria for youth ministry.
After all, at best our greatest teaching will probably do no more than make a tiny dent in their character or faith. They probably won't remember what they learned on xx day of yy year from your teaching. But they will remember that you loved them when others may not have, and that you loved them in Christ's name. So just love them. Whatever you do, just love them.