Teach them about Oliver Cromwell’s rule: “I beseech you, in the bowels of Christ, think it possible that you may be mistaken.”
Leave room for your mind to be changed by new evidence or perspective.
What I most want to teach you this year is that you can always trust me. I will always love you, take care of you and never harm you. You may not always like me, but you can always trust me.
Never post a pic to social media that you wouldn't want Grandma to see. NEVER send or ask to receive naked pictures.
It's tacky, gross, illegal and not worth it. Even if "everyone does it". It's rude and disrespectful.
One regret I have is how sure I was that I was in the right. Looking back I can see now that there were plenty of times when I was the a-hole. I wish I had been able to be circumspect.
When the child is feeling upset or out of control, that is not the time to teach a lesson. Share your calm, be a safe place for them. When they’re feeling better, THEN teach the lesson.
Teach your pets they can trust you. Take care of them. Treat them with tenderness. Teach them how to behave. (Unless it's a cat. You can't teach cats anything.)
One of the funny/sensitive things about puberty is that kids can be the same age chronologically while being wildly varied in terms of development. Kid might be 6 feet tall in seventh grade or be a senior in high school and still not shaving. Everyone is self conscious, praying to avoid embarrassment. It’s all just part of growing up. Be kind to yourself and to your equally mortified peers.
Being well-read is better (and cheaper) than an advanced degree, especially for broader education. Stay curious and read!! Fiction, non-fiction, biographies ...