A resource that I refer back to periodically is a book called Character Building: A Guide for Parents and Teachers by David Isaacs. It outlines the general virtues that parents should be developing in their children at various ages.
From 16 to 18 years old
The first virtues we emphasize for this age level are based on the ability to reason things out intelligently; in other words, it is almost impossible to develop virtues fully without a certain intellectual capacity. ...
When we come to describing how these virtues work, the reader will be able to see why I say this. For example, I speak about 'continually gathering information'; 'thinking out the consequences'; 'protecting a series of values'; 'recognizing various factors influencing situation'; 'recognizing one's own shortcomings'; etc. Therefore, it seems good to emphasize these virtues at the stage when young people are more intellectually developed. ...
In the earlier stage dangers arose out of letting their passions 'do their own thing'; in this later stage the main danger is mistaken ideas. Hence the need for flexibility so that they can learn from different situations without saying goodbye to the standards governing their personal behavior. ...
Parents should realize that already at these ages it is very difficult to require children to do things: nor is it such a good idea, anyway. Rather what they should be doing is really requiring the children to think things out before taking decisions; they should be reminding them of the importance of adopting standards which can form a basis for acting reasonably.