Let them fail
Let them fall
Let them experience what the word "HOT" means....as painful as it is to watch them learn it..the earlier they learn what it means, the faster they progress.
I've got a 24yr old, a 22yr old and a soon to be 20yr old. The worry NEVER stops.
One HUGE thing I have learned that gave me a great advantage over others with kids my age; I was ALWAYS honest with them. Like BRUTALLY honest. Our middle child was not going to be fooled by "santa" any more after she was 6. She asked and wanted a straight answer. we gave it to her. And made her promise not to tell her older brother or younger sister.
My son asked what beer tasted like when he was 8. Handed him a Red oak. Didn't develop a taste for it until he was 20
Sometimes you don't WANT to know things...but when you've promised your child you would tell them anything they wanted to know, just ask...believe me it gets reciprocated.
One thing to remember (that I had to remind my wife of DAILY) is NEVER ask a middle schooler, or teenager more than 3 questions. Over what time period you ask? YES. I've had so many parents ask me how I was able to remain so close to my kids, and not have them push me away. Simple. Never ask more than 3 questions. And if possible, never let those questions have a simple answer. I.E. "Did you have a good day?" Answer can be : yes or no. Instead, ask; Tell me who won the award for being a dillweed today?
And yes...as they get older they will have less to do with you. Their friends take priority, and many times their friends (and society) paints parents as adversary's. However...you CAN have a relationship with your child, not try to be "buddy dad" and also have their respect. You just have to remember respect is mutual. Trust is mutual. And love is a CHOICE. Give them a reason to love you by taking them at their word, trusting THEM with decisions, and letting them make mistakes and learning from them. And encourage them! tell them you are proud of them (regardless of whether they lived up to YOUR expectations) and tell them you got their back no matter what. It's so very hard to watch your children "learn the hard way" sometimes......but SO very worth it to see them grow and mature.