If your child is 11 or 12, it's a good time to start discussing issues around drinking. You might begin a conversation by stating that you recently learned that the 13 is the average age for kids to start drinking. Ask your children for their thoughts on drinking. Share concerns you have about underage drinking.
For these types of ongoing issues, plan on having many short conversations while your children are growing up. Knowing that you are open to discussing tough topics will help your kids feel more comfortable approaching you in the future.