It's neccessary for children should learn about failure and imperfection. When I tell my child about the problems I faced and failures I made in life, I am avoiding making them feel like they are perfect and making them understand that it is okay to make mistakes and failure is a way to transform.
Hopefully, it doesn't backfire and they try to repeat some of the failures that you shared with them, and them doing it because they think they can get away with it.
From experience, my parents told me about their mistakes of drinking underage and getting caught. It just made me extra sneaky, and I never got "caught". However, I'm sure they
knew that I drank after picking me up the next day from a party (that was just a "sleepover") because alcohol, or the afterbreath of consuming that much, is still quite distinct the morning after, not to mention the smell of cigarettes.
Teens will be teens, but that approach didn't work with me.
I'm going to try something different because we are in a society that tolerates drinking to a strong degree here in Japan and tell my daughter upfront that I know that they might be introduced to drinking while out. And, tell her that, if she chooses to drink, it's okay, but not to get sloppy drunk where she could stumble, fall, and maybe hurt herself, or find her in a situation where others may harm her. With that in mind, I'm going to tell her to give me a call at any hour and I will pick her up within 10 minutes, as she has GPS tracking, no questions asked.