As long as you tell them what they want to hear, it's all good. As soon as you say something they don't like, you are the enemy.
If you haven't already watched your child go through something serious, think about what that might feel like. Imagine them coming home or calling you with a pressing matter, especially if it's a situation you have discussed over and over with them.
There were so many talks I did not receive as a child that I've tried my best to ensure I had with my sons.
There is so much satisfaction in knowing that you have set your kids up for success. You cannot guarantee their outcome, but you can take pleasure in the fact that you've prepared them for victory.