It needs to begin all the way back in the seminary.   No matter how badly we think we need priests, we don't need to let the fragile types in and have them fall apart in parishes, and fall into pursuit of "passions" however disordered. 

Being a priest is far too demanding to let wholly unsuitable men/boys into the seminary.  If the candidates are vain, whiny, overly emotional, dramatic, physically soft...those aren't good signs that the roots run deep.   Sturdy, steady, calm, not overly concerned with their physical appearance, with strong bearing.