Most of my practical advice is nothing too special. You could get video previews for some shows, or get descriptions or read reviews and explain what it's about

Most of my practical advice is nothing too special. You could get video previews for some shows, or get descriptions or read reviews and explain what it's about to child and see if he likes the sound of it. You can offer to get more of the same kind as something he likes. Parents already do these things at least sometimes. What parents don't generally do is have an attitude of trying to get whatever their child likes. They do that "within reasonable limits". Reasonable being a matter of their own judgment. They have preconceived ideas about what shows are bad, and try to avoid their child finding out about them instead of refuting the bad ideas. They fear "bad influences", instead of thinking that the worse an idea is, the less persuasive it is. One consequence of this attitude is that sometimes children want something, and their parents refuse, supposedly for the child's own good, and the child gets upset. Plenty of parents would, if their kid saw an episode of Veggie Tales (or whatever) and liked and repeated some ideas from it, say "omg the evil christians are polluting his mind" and forbid him from seeing the second episode that he's looking forward to. That's the wrong approach. Keeping people ignorant of ideas you think are bad is not the path to the truth.