I'm not a parent myself but I have plenty of friends who are, and of all their strategies I think my favourite is the one of encouraging children from a young age to "make good decisions"
If all children hear is "Don't do that, don't do this, don't talk to them" then ultimately and eventually they are going to rebel, just to see what happens (and I've seen that side, too.)
Kids need to learn to make decisions for themselves, and sometimes that can even mean allowing them have bad and unpleasant outcomes (in minor and non-dangerous ways)
When kids are empowered to think for themselves and also to understand consequence, I think they are much better equpped to handle anything, including weird Internet trends that can get you killed.