In raising my daughters and working in YW, I have found that speaking plainly with my teenagers is a policy that works for me. I do not want them to come back and say they didn't understand what I wanted or expected. I feel that dropping hints leaves too much room for interpretation. We need to fight the evils in this world with clear-cut boundaries. Elder Holland gives a wonderful talk, a portion of which is on youth.lds.org. This, and another video presentation by President Monson, were played at our Stake Standards Night. These are worth sharing for those who have not seen them.
I love how President Monson reminds us that we are never alone when we stand with our Father in Heaven!
Heavenly Father is the author of the For the Strength of Youth pamphlet through his inspired prophets. As parents and leaders, we find our young people are strong-willed. This is an important characteristic to channel for good. It can become courage! We can help them find this courage by teaching them and talking with them about the standards their Heavenly Father has set for them. In gaining a testimony of these principles, these youth can dare to have a purpose, dare to choose the right, and dare to choose the Temple.
(Many more wonderful videos, talks, and resources can be found at youth.lds.org)