Parents: Be adamant
Alcohol has become much too easy for teens to acquire without the help of adults; therefore, I think adults are obligated to exhibit some degree of responsibility by more adamantly discouraging under aged youth to drink.
A way of doing this is making the consequence for under-aged drinking more severe. This may possibly dissuade teenagers from drinking at a young age.
I also believe adults distributing alcohol to youth should be even more severely punished than the youth themselves because they are expected to be positive role models for kids. Even if their kids are not interested in drinking, kids' personalities and tendencies reflect their parents'; whether they are positive or not.
I don't believe the majority of adults demonstrate enough, if any, responsibility when drinking, nor provide a good example for youth. If their parents are alcoholics, why shouldn't teens be allowed to drink as well?
Parents: Be honest
I'm not sure if there are any adults around today who can honestly say that there isn't something they regret doing in their youth.
However, I think that some of these things have gotten more extreme over the years, especially underage drinking.
Within the sphere of people I encounter or overhear in the hallways of my school, underage drinking is not something uncommon by any means.
Even with the increased laws regarding selling alcohol to youth, many teens get it from older people, have older siblings or even take it from their parents.
I have noticed how many adults seem to be unsure what to do about the problem of underage drinking. What many adults fail to see is the fact that if you tell a teenager not to do something, even if potentially harmful, that urge to experiment or even to spite the authority may prevail.
I believe that parents and guardians need to talk to their kids at a young age about drinking, and to do so in-depth. Giving accurate and true information to youth is what helps them make informed decisions about drinking, and keeping that information from them is what causes tragedies.